[{"OA_place":"publisher","publication_status":"published","article_processing_charge":"No","oa_version":"Published Version","file":[{"success":1,"date_updated":"2026-02-16T09:33:56Z","file_size":4020466,"checksum":"2faec710fd04f927aa43deb57e35c9b2","file_name":"2026_AstronomyAstrophysics_Yu.pdf","content_type":"application/pdf","relation":"main_file","date_created":"2026-02-16T09:33:56Z","creator":"dernst","access_level":"open_access","file_id":"21227"}],"year":"2026","scopus_import":"1","abstract":[{"text":"Context. AM Canum Venaticorum (AM CVn) stars are ultra-compact binary systems composed of a white dwarf primary accreting from a hydrogen-deficient donor. They play a crucial role in astrophysics as potential progenitors of Type Ia supernovae and as laboratories for gravitational wave studies. However, their formation and evolutionary history remain incomplete. Three formation channels have been discussed in the literature: the white dwarf, He-star, and cataclysmic variable channels.\r\n\r\nAims. The chemical composition of the accretor atmosphere reflects the material transferred from the donor. In this work we took the first accurate measurements of the fundamental parameters of the accreting white dwarf in ZTF J225237.05−051917.4, including the abundances of key elements such as carbon, nitrogen, and silicon, by analysing ultraviolet spectra obtained with the Hubble Space Telescope (HST). These measurements provide new insight into the evolutionary history of the system and, together with existing optical observations, establish it as a benchmark to develop our pipeline, paving the way for its application to a larger sample of AM CVn systems.\r\n\r\nMethods. We determined the binary parameters through photometric analysis and constrained the atmospheric parameters of the white dwarf accretor, including its effective temperature, surface gravity, and chemical abundances, by fitting the HST ultraviolet spectrum with synthetic spectral models. We then inferred the system’s formation channel by comparing the results with theoretical evolutionary models.\r\n\r\nResults. According to our measurements, the accretor’s effective temperature (Teff) is 23 300 ± 600 K and the surface gravity (log g) is 8.4 ± 0.3, which imply an accretor mass (MWD) of 0.86 ± 0.16 M⊙. We find a high nitrogen-to-carbon abundance ratio by mass of > 153.\r\n\r\nConclusions. The accretor is significantly hotter than previous estimates based on simplified blackbody fits to the spectral energy distribution, underscoring the importance of detailed spectral modelling for accurately determining system parameters. Our results show that ultraviolet spectroscopy is well suited to constraining the formation channels of AM CVn systems. Of the three proposed formation channels, the He-star channel can be excluded given the high nitrogen-to-carbon ratio. Our results are consistent with both the white dwarf and cataclysmic variable channels.","lang":"eng"}],"date_updated":"2026-02-16T09:36:24Z","arxiv":1,"month":"02","date_published":"2026-02-01T00:00:00Z","publisher":"EDP Sciences","file_date_updated":"2026-02-16T09:33:56Z","publication":"Astronomy and Astrophysics","_id":"21160","day":"01","doi":"10.1051/0004-6361/202557568","acknowledgement":"We thank Lars Bildsten for valuable insights and discussions. We acknowledge with thanks the variable star observations from the\r\nAAVSO International Database contributed by observers worldwide and used in this research. We thank the members of the Spanish Observers of Supernovae\r\n(ObSN) group for their valuable photometric contributions. This research was\r\nsupported by Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2121 “Quantum Universe”\r\n– 390833306. Co-funded by the European Union (ERC, CompactBINARIES,\r\n101078773). Views and opinions expressed are however those of the author(s)\r\nonly and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority\r\ncan be held responsible for them. DB acknowledges support from the São Paulo\r\nResearch Foundation (FAPESP), Brazil, Process Numbers #2024/03736-2 and\r\n#2025/00817-4. MRS is supported by Fondecyt (grant 1221059). MJG acknowledges support from the European Research Council through ERC Advanced\r\nGrant No. 101054731, from the National Aeronautics and Space Administration under grants 80NSSC24K0436, 80NSSC22K0479, and 80NSSC24K0380,\r\nand from the National Science Foundation under grant AST-2205736. PJG\r\nis supported by NRF SARChI grant 111692. PR-G acknowledges support by\r\nthe Agencia Estatal de Investigación del Ministerio de Ciencia e Innovación\r\n(MCIN/AEI) and the European Regional Development Fund (ERDF) under grant\r\nPID2021–124879NB–I00. DS is supported by the UK Science and Technology Facilities Council (STFC, grant numbers ST/T007184/1, ST/T003103/1,\r\nand ST/T000406/1). OT acknowledges Proyectos Internos USM 2025, PI-LII2025-03. GT was supported by grants IN109723 from the Programa de Apoyo a\r\nProyectos de Investigación e Innovación Tecnológica (PAPIIT). This project has\r\nreceived funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 101020057).","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"oa":1,"department":[{"_id":"IlCa"}],"citation":{"chicago":"Yu, W., A. F. Pala, T. Kupfer, B. T. Gänsicke, D. Koester, D. Belloni, T. L.S. Wong, et al. “The Evolutionary History of Ultra-Compact Accreting Binaries: I. Chemical Abundances and the Formation Channel of the Eclipsing AM CVn System ZTF J225237.05-051917.4 from HST Spectroscopy.” <i>Astronomy and Astrophysics</i>. EDP Sciences, 2026. <a href=\"https://doi.org/10.1051/0004-6361/202557568\">https://doi.org/10.1051/0004-6361/202557568</a>.","ieee":"W. Yu <i>et al.</i>, “The evolutionary history of ultra-compact accreting binaries: I. Chemical abundances and the formation channel of the eclipsing AM CVn system ZTF J225237.05-051917.4 from HST spectroscopy,” <i>Astronomy and Astrophysics</i>, vol. 706. EDP Sciences, 2026.","ista":"Yu W, Pala AF, Kupfer T, Gänsicke BT, Koester D, Belloni D, Wong TLS, Schreiber MR, van Roestel JC, Brown AJ, Waagen EO, González-Carballo JL, Bednarz S, Bernacki K, De Martino D, Fernández Mañanes E, González Farfán R, Green MJ, Groot PJ, Hambsch FJ, Knigge C, Martin-Velasco JL, Morales-Aimar M, Myers G, Naves Nogues R, Poggiani R, Popowicz A, Ramsay G, Reina-Lorenz E, Rodríguez-Gil P, Salto-González JL, Sion EM, Steeghs D, Szkody P, Toloza O, Tovmassian G. 2026. The evolutionary history of ultra-compact accreting binaries: I. Chemical abundances and the formation channel of the eclipsing AM CVn system ZTF J225237.05-051917.4 from HST spectroscopy. Astronomy and Astrophysics. 706, A14.","apa":"Yu, W., Pala, A. F., Kupfer, T., Gänsicke, B. T., Koester, D., Belloni, D., … Tovmassian, G. (2026). The evolutionary history of ultra-compact accreting binaries: I. Chemical abundances and the formation channel of the eclipsing AM CVn system ZTF J225237.05-051917.4 from HST spectroscopy. <i>Astronomy and Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202557568\">https://doi.org/10.1051/0004-6361/202557568</a>","short":"W. Yu, A.F. Pala, T. Kupfer, B.T. Gänsicke, D. Koester, D. Belloni, T.L.S. Wong, M.R. Schreiber, J.C. van Roestel, A.J. Brown, E.O. Waagen, J.L. González-Carballo, S. Bednarz, K. Bernacki, D. De Martino, E. Fernández Mañanes, R. González Farfán, M.J. Green, P.J. Groot, F.J. Hambsch, C. Knigge, J.L. Martin-Velasco, M. Morales-Aimar, G. Myers, R. Naves Nogues, R. Poggiani, A. Popowicz, G. Ramsay, E. Reina-Lorenz, P. Rodríguez-Gil, J.L. Salto-González, E.M. Sion, D. Steeghs, P. Szkody, O. Toloza, G. Tovmassian, Astronomy and Astrophysics 706 (2026).","ama":"Yu W, Pala AF, Kupfer T, et al. The evolutionary history of ultra-compact accreting binaries: I. Chemical abundances and the formation channel of the eclipsing AM CVn system ZTF J225237.05-051917.4 from HST spectroscopy. <i>Astronomy and Astrophysics</i>. 2026;706. doi:<a href=\"https://doi.org/10.1051/0004-6361/202557568\">10.1051/0004-6361/202557568</a>","mla":"Yu, W., et al. “The Evolutionary History of Ultra-Compact Accreting Binaries: I. Chemical Abundances and the Formation Channel of the Eclipsing AM CVn System ZTF J225237.05-051917.4 from HST Spectroscopy.” <i>Astronomy and Astrophysics</i>, vol. 706, A14, EDP Sciences, 2026, doi:<a href=\"https://doi.org/10.1051/0004-6361/202557568\">10.1051/0004-6361/202557568</a>."},"type":"journal_article","article_type":"original","date_created":"2026-02-08T23:02:49Z","ddc":["520"],"article_number":"A14","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","PlanS_conform":"1","volume":706,"has_accepted_license":"1","OA_type":"diamond","license":"https://creativecommons.org/licenses/by/4.0/","quality_controlled":"1","title":"The evolutionary history of ultra-compact accreting binaries: I. Chemical abundances and the formation channel of the eclipsing AM CVn system ZTF J225237.05-051917.4 from HST spectroscopy","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"intvolume":"       706","status":"public","language":[{"iso":"eng"}],"external_id":{"arxiv":["2512.04147"]},"author":[{"first_name":"W.","full_name":"Yu, W.","last_name":"Yu"},{"full_name":"Pala, A. F.","first_name":"A. F.","last_name":"Pala"},{"full_name":"Kupfer, T.","first_name":"T.","last_name":"Kupfer"},{"last_name":"Gänsicke","first_name":"B. T.","full_name":"Gänsicke, B. T."},{"last_name":"Koester","first_name":"D.","full_name":"Koester, D."},{"last_name":"Belloni","full_name":"Belloni, D.","first_name":"D."},{"last_name":"Wong","first_name":"T. L.S.","full_name":"Wong, T. L.S."},{"first_name":"M. R.","full_name":"Schreiber, M. R.","last_name":"Schreiber"},{"id":"4d122fc8-6083-11f0-87a5-97d68b860333","last_name":"van Roestel","full_name":"van Roestel, Joannes C","first_name":"Joannes C"},{"full_name":"Brown, A. J.","first_name":"A. J.","last_name":"Brown"},{"first_name":"E. O.","full_name":"Waagen, E. O.","last_name":"Waagen"},{"full_name":"González-Carballo, J. L.","first_name":"J. L.","last_name":"González-Carballo"},{"last_name":"Bednarz","first_name":"S.","full_name":"Bednarz, S."},{"first_name":"K.","full_name":"Bernacki, K.","last_name":"Bernacki"},{"full_name":"De Martino, D.","first_name":"D.","last_name":"De Martino"},{"last_name":"Fernández Mañanes","first_name":"E.","full_name":"Fernández Mañanes, E."},{"full_name":"González Farfán, R.","first_name":"R.","last_name":"González Farfán"},{"last_name":"Green","first_name":"M. J.","full_name":"Green, M. J."},{"last_name":"Groot","full_name":"Groot, P. J.","first_name":"P. J."},{"full_name":"Hambsch, F. J.","first_name":"F. J.","last_name":"Hambsch"},{"last_name":"Knigge","first_name":"C.","full_name":"Knigge, C."},{"full_name":"Martin-Velasco, J. L.","first_name":"J. L.","last_name":"Martin-Velasco"},{"last_name":"Morales-Aimar","full_name":"Morales-Aimar, M.","first_name":"M."},{"last_name":"Myers","first_name":"G.","full_name":"Myers, G."},{"last_name":"Naves Nogues","first_name":"R.","full_name":"Naves Nogues, R."},{"last_name":"Poggiani","first_name":"R.","full_name":"Poggiani, R."},{"full_name":"Popowicz, A.","first_name":"A.","last_name":"Popowicz"},{"full_name":"Ramsay, G.","first_name":"G.","last_name":"Ramsay"},{"full_name":"Reina-Lorenz, E.","first_name":"E.","last_name":"Reina-Lorenz"},{"full_name":"Rodríguez-Gil, P.","first_name":"P.","last_name":"Rodríguez-Gil"},{"last_name":"Salto-González","first_name":"J. L.","full_name":"Salto-González, J. L."},{"last_name":"Sion","first_name":"E. M.","full_name":"Sion, E. M."},{"first_name":"D.","full_name":"Steeghs, D.","last_name":"Steeghs"},{"first_name":"P.","full_name":"Szkody, P.","last_name":"Szkody"},{"full_name":"Toloza, O.","first_name":"O.","last_name":"Toloza"},{"last_name":"Tovmassian","first_name":"G.","full_name":"Tovmassian, G."}]},{"author":[{"id":"662f1873-cab4-11f0-a719-8087d302868d","full_name":"Liagre, Bastien Raymond Bernard","first_name":"Bastien Raymond Bernard","last_name":"Liagre"},{"id":"502cfd30-32c1-11ee-a9a4-d8dad5c6739e","last_name":"Desai","first_name":"Aayush A","full_name":"Desai, Aayush A"},{"first_name":"Lukas","full_name":"Einramhof, Lukas","last_name":"Einramhof","id":"f1497a1a-72ef-11ef-b75a-fd877bbf6e8c"},{"full_name":"Bugnet, Lisa Annabelle","first_name":"Lisa Annabelle","orcid":"0000-0003-0142-4000","last_name":"Bugnet","id":"d9edb345-f866-11ec-9b37-d119b5234501"}],"external_id":{"arxiv":["2511.05314 "]},"language":[{"iso":"eng"}],"intvolume":"       707","status":"public","DOAJ_listed":"1","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"title":"Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting","quality_controlled":"1","has_accepted_license":"1","OA_type":"diamond","volume":707,"PlanS_conform":"1","article_number":"A321","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_type":"original","corr_author":"1","ddc":["520"],"date_created":"2026-04-05T22:01:32Z","oa":1,"department":[{"_id":"LiBu"},{"_id":"IlCa"},{"_id":"GradSch"}],"type":"journal_article","citation":{"mla":"Liagre, Bastien Raymond Bernard, et al. “Near-Degeneracy Effects in Quadrupolar Mixed Modes: From an Asymptotic Description to Data Fitting.” <i>Astronomy and Astrophysics</i>, vol. 707, A321, EDP Sciences, 2026, doi:<a href=\"https://doi.org/10.1051/0004-6361/202558023\">10.1051/0004-6361/202558023</a>.","ama":"Liagre BRB, Desai AA, Einramhof L, Bugnet LA. Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting. <i>Astronomy and Astrophysics</i>. 2026;707. doi:<a href=\"https://doi.org/10.1051/0004-6361/202558023\">10.1051/0004-6361/202558023</a>","short":"B.R.B. Liagre, A.A. Desai, L. Einramhof, L.A. Bugnet, Astronomy and Astrophysics 707 (2026).","apa":"Liagre, B. R. B., Desai, A. A., Einramhof, L., &#38; Bugnet, L. A. (2026). Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting. <i>Astronomy and Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202558023\">https://doi.org/10.1051/0004-6361/202558023</a>","ista":"Liagre BRB, Desai AA, Einramhof L, Bugnet LA. 2026. Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting. Astronomy and Astrophysics. 707, A321.","ieee":"B. R. B. Liagre, A. A. Desai, L. Einramhof, and L. A. Bugnet, “Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting,” <i>Astronomy and Astrophysics</i>, vol. 707. EDP Sciences, 2026.","chicago":"Liagre, Bastien Raymond Bernard, Aayush A Desai, Lukas Einramhof, and Lisa Annabelle Bugnet. “Near-Degeneracy Effects in Quadrupolar Mixed Modes: From an Asymptotic Description to Data Fitting.” <i>Astronomy and Astrophysics</i>. EDP Sciences, 2026. <a href=\"https://doi.org/10.1051/0004-6361/202558023\">https://doi.org/10.1051/0004-6361/202558023</a>."},"publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"acknowledgement":"We thank the referee for their careful and constructive report, which has substantially enhanced both the quality and clarity of the manuscript. L. Bugnet and L. Einramhof gratefully acknowledge support from the European Research Council (ERC) under the Horizon Europe programme (Calcifer; Starting Grant agreement N°101165631). While partially funded by the European Union, views and opinions expressed are, however, those of the authors only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. The authors acknowledge the great support and feedback provided during the redaction of this article by Pr. Rafael García and Pr. Savita Mathur. We would also like to thank Dr. Emily Hatt for her insights on uncertainty estimates. The authors also thank the members of the Asteroseismology and Stellar Dynamics group of the Institute of Science and Technology Austria (ISTA) for very useful discussions: L. Barrault, S.B. Das, K. Smith. This paper includes data collected by the Kepler mission and obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the Kepler mission is provided by the NASA Science Mission Directorate. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5–26555. Software: AstroPy (Astropy Collaboration 2013, 2018), Matplotlib (Hunter 2007), NumPy (Harris et al. 2020), SciPy (Virtanen et al. 2020), emcee (Foreman-Mackey et al. 2013), celerite (Foreman-Mackey et al. 2017), slepc4py (Dalcin et al. 2011; Hernandez et al. 2005), KADACS (García et al. 2011), sloscillations (Kuszlewicz et al. 2019, 2023).","doi":"10.1051/0004-6361/202558023","day":"01","_id":"21658","file_date_updated":"2026-04-07T09:00:50Z","publication":"Astronomy and Astrophysics","publisher":"EDP Sciences","date_published":"2026-03-01T00:00:00Z","abstract":[{"lang":"eng","text":"Dipolar (ℓ = 1) mixed modes have revealed a surprisingly weak differential rotation between the core and the envelope of evolved solar-like stars. Quadrupolar (ℓ = 2) mixed modes also contain information regarding internal dynamics but are very rarely characterised due to their low amplitude and the challenging identification of adjacent or overlapping rotationally split multiplets affected by near-degeneracy effects. We aim to extend the broadly used asymptotic seismic diagnostics beyond ℓ = 1 mixed modes by developing an analogue asymptotic description of ℓ = 2 mixed modes while explicitly accounting for near-degeneracy effects that distort their rotational multiplets. We have derived a new asymptotic formulation of near-degenerate mixed ℓ = 2 modes that describes off-diagonal terms representing the interaction between modes of adjacent radial orders. This formalism, expressed directly in the mixed-mode basis, provides analytical expressions for the near-degeneracy effects. We implemented the formalism within a global Bayesian mode-fitting framework for a direct fit of all ℓ = 0, 1, 2 modes in the power spectrum density. We were able to asymptotically model the asymmetric rotational splitting present in various radial orders of ℓ = 2 modes observed in young red giant stars without the need for any numerical stellar modelling. We applied our formalism to the Kepler target KIC 7341231, and it yielded core and envelope rotation rates consistent with previous numerical modelling while providing improved constraints from the global and model-independent approach. We also characterised the new target, KIC 8179973, measuring its rotation rate and mixed-mode parameters for the first time. As our framework relies on a direct global fit, it allows for much better precision on the asteroseismic parameters and rotation rate estimates than standard methods, yielding better constraints for rotation inversions. We have placed the first observational constraints on the asymptotic ℓ = 2 mixed-mode parameters (ΔΠ2, q2, and εg, 2), thus paving the way towards the use of asymptotic seismology beyond ℓ = 1 mixed modes."}],"scopus_import":"1","year":"2026","month":"03","date_updated":"2026-04-07T09:01:44Z","arxiv":1,"oa_version":"Published Version","file":[{"access_level":"open_access","creator":"dernst","date_created":"2026-04-07T09:00:50Z","relation":"main_file","file_id":"21664","file_size":12287607,"success":1,"date_updated":"2026-04-07T09:00:50Z","content_type":"application/pdf","file_name":"2026_AstronomyAstrophysics_Liagre.pdf","checksum":"560cac19dc70184626b85e71a26ee22e"}],"OA_place":"publisher","publication_status":"published","article_processing_charge":"No"},{"quality_controlled":"1","title":"The White Dwarf initial–final mass relation from open clusters in Gaia DR3","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"DOAJ_listed":"1","intvolume":"       996","status":"public","language":[{"iso":"eng"}],"external_id":{"arxiv":["2510.24877"]},"author":[{"last_name":"Miller","full_name":"Miller, David R.","first_name":"David R."},{"first_name":"Ilaria","full_name":"Caiazzo, Ilaria","orcid":"0000-0002-4770-5388","last_name":"Caiazzo","id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d"},{"first_name":"Jeremy","full_name":"Heyl, Jeremy","last_name":"Heyl"},{"first_name":"Harvey B.","full_name":"Richer, Harvey B.","last_name":"Richer"},{"first_name":"Mark A.","full_name":"Hollands, Mark A.","last_name":"Hollands"},{"last_name":"Tremblay","first_name":"Pier Emmanuel","full_name":"Tremblay, Pier Emmanuel"},{"full_name":"El-Badry, Kareem","first_name":"Kareem","last_name":"El-Badry"},{"full_name":"Rodriguez, Antonio C.","first_name":"Antonio C.","last_name":"Rodriguez"},{"last_name":"Vanderbosch","full_name":"Vanderbosch, Zachary P.","first_name":"Zachary P."}],"article_type":"original","date_created":"2026-04-12T22:01:52Z","ddc":["520"],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"69","PlanS_conform":"1","keyword":["White dwarf stars","Open star clusters","Compact objects","Stellar evolution"],"volume":996,"has_accepted_license":"1","OA_type":"gold","file_date_updated":"2026-04-13T08:36:50Z","issue":"1","publication":"The Astrophysical Journal","_id":"21725","day":"01","doi":"10.3847/1538-4357/ae18c8","acknowledgement":"The authors would like to thank the anonymous referee for their constructive feedback, which helped improve the clarify of the manuscript. This work was supported in part by the Natural Sciences and Engineering Research Council of Canada Discovery grants Nos. DG-RGPIN-2022-03051 and DG-RGPIN-2023-04486. This research received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program number 101002408 (MOS100PC). This work includes results based on observations obtained at the international Gemini Observatory, a program of NSF’s NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation on behalf of the Gemini Observatory partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Gemini spectra were processed using the DRAGONS package (K. Labrie et al. 2023). LRIS spectra were reduced using the Lpipe pipeline (D. A. Perley 2019).\r\n\r\nFacilities: Gaia - (DR2 & DR3), Gemini:Gillett - Gillett Gemini North Telescope (GMOS-N), Gemini:South - Gemini South Telescope (GMOS-S), Keck:I - KECK I Telescope (LRIS).\r\n\r\nSoftware: Astropy (Astropy Collaboration et al. 2013,2018, 2022), emcee (D. Foreman-Mackey et al. 2013).","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"oa":1,"citation":{"apa":"Miller, D. R., Caiazzo, I., Heyl, J., Richer, H. B., Hollands, M. A., Tremblay, P. E., … Vanderbosch, Z. P. (2026). The White Dwarf initial–final mass relation from open clusters in Gaia DR3. <i>The Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/ae18c8\">https://doi.org/10.3847/1538-4357/ae18c8</a>","ista":"Miller DR, Caiazzo I, Heyl J, Richer HB, Hollands MA, Tremblay PE, El-Badry K, Rodriguez AC, Vanderbosch ZP. 2026. The White Dwarf initial–final mass relation from open clusters in Gaia DR3. The Astrophysical Journal. 996(1), 69.","short":"D.R. Miller, I. Caiazzo, J. Heyl, H.B. Richer, M.A. Hollands, P.E. Tremblay, K. El-Badry, A.C. Rodriguez, Z.P. Vanderbosch, The Astrophysical Journal 996 (2026).","mla":"Miller, David R., et al. “The White Dwarf Initial–Final Mass Relation from Open Clusters in Gaia DR3.” <i>The Astrophysical Journal</i>, vol. 996, no. 1, 69, IOP Publishing, 2026, doi:<a href=\"https://doi.org/10.3847/1538-4357/ae18c8\">10.3847/1538-4357/ae18c8</a>.","ama":"Miller DR, Caiazzo I, Heyl J, et al. The White Dwarf initial–final mass relation from open clusters in Gaia DR3. <i>The Astrophysical Journal</i>. 2026;996(1). doi:<a href=\"https://doi.org/10.3847/1538-4357/ae18c8\">10.3847/1538-4357/ae18c8</a>","chicago":"Miller, David R., Ilaria Caiazzo, Jeremy Heyl, Harvey B. Richer, Mark A. Hollands, Pier Emmanuel Tremblay, Kareem El-Badry, Antonio C. Rodriguez, and Zachary P. Vanderbosch. “The White Dwarf Initial–Final Mass Relation from Open Clusters in Gaia DR3.” <i>The Astrophysical Journal</i>. IOP Publishing, 2026. <a href=\"https://doi.org/10.3847/1538-4357/ae18c8\">https://doi.org/10.3847/1538-4357/ae18c8</a>.","ieee":"D. R. Miller <i>et al.</i>, “The White Dwarf initial–final mass relation from open clusters in Gaia DR3,” <i>The Astrophysical Journal</i>, vol. 996, no. 1. IOP Publishing, 2026."},"type":"journal_article","department":[{"_id":"IlCa"}],"OA_place":"publisher","publication_status":"published","article_processing_charge":"Yes","oa_version":"Published Version","file":[{"file_id":"21733","creator":"dernst","access_level":"open_access","relation":"main_file","date_created":"2026-04-13T08:36:50Z","content_type":"application/pdf","checksum":"65a8237a519188af83b6dc4d47ad85fa","file_name":"2026_AstrophysicalJournal_Miller.pdf","file_size":19310053,"date_updated":"2026-04-13T08:36:50Z","success":1}],"abstract":[{"text":"The initial–final mass relation (IFMR) links a star’s birth mass to the mass of its white dwarf (WD) remnant, providing key constraints on stellar evolution. Open clusters offer the most straightforward way to empirically determine the IFMR, as their well-defined ages allow for direct progenitor lifetime estimates. We construct the most comprehensive open cluster WD IFMR to date by combining new spectroscopy of 22 WDs with an extensive literature review of WDs with strong cluster associations. To minimize systematics, we restrict our analysis to spectroscopically confirmed hydrogen-atmosphere (DA) WDs consistent with single-stellar origins. We separately analyze a subset with reliable Gaia-based astrometric membership assessments, as well as a full sample that adds WDs with strong cluster associations whose membership cannot be reliably assessed with Gaia. The Gaia-based sample includes 69 spectroscopically confirmed DA WDs, more than doubling the sample size of previous Gaia-based open cluster IFMRs. The full sample, which includes 53 additional literature WDs,\r\nincreases the total number of cluster WDs by over 50% relative to earlier works. We provide functional forms for both the Gaia-based and full-sample IFMRs. The Gaia-based result useful for Mi � 2.67 M⊙ is Mf = [0.179 0.100H (Mi 3.84 M )] × (Mi 3.84 M ) + 0.628 M , where H(x) is the Heaviside step function. Comparing our IFMR to recent literature, we identify significant deviations from best-fit IFMRs derived from both Gaia-based volume-limited samples of field WDs and double WD binaries, with the largest discrepancy occurring for initial masses of about 5 M⊙.","lang":"eng"}],"scopus_import":"1","year":"2026","arxiv":1,"date_updated":"2026-04-13T08:39:39Z","month":"01","date_published":"2026-01-01T00:00:00Z","publisher":"IOP Publishing"},{"oa":1,"type":"journal_article","citation":{"short":"A.-A. Cristea, I. Caiazzo, T. Cunningham, J.C. Raymond, S. Vennes, A. Kawka, A.A. Desai, D.R. Miller, J.J. Hermes, J. Fuller, J. Heyl, J. van Roestel, K.B. Burdge, A.C. Rodriguez, I. Pelisoli, B.T. Gänsicke, P. Szkody, S.J. Kenyon, Z. Vanderbosch, A. Drake, L. Ferrario, D. Wickramasinghe, V.R. Karambelkar, S. Justham, R. Pakmor, K. El-Badry, T. Prince, S.R. Kulkarni, M.J. Graham, F.J. Masci, S.L. Groom, J. Purdum, R. Dekany, E.C. Bellm, Astronomy &#38; Astrophysics 706 (2026).","mla":"Cristea, Andrei-Alexandru, et al. “A Half Ring of Ionized Circumstellar Material Trapped in the Magnetosphere of a White Dwarf Merger Remnant.” <i>Astronomy &#38; Astrophysics</i>, vol. 706, A188, EDP Sciences, 2026, doi:<a href=\"https://doi.org/10.1051/0004-6361/202556432\">10.1051/0004-6361/202556432</a>.","ama":"Cristea A-A, Caiazzo I, Cunningham T, et al. A half ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant. <i>Astronomy &#38; Astrophysics</i>. 2026;706. doi:<a href=\"https://doi.org/10.1051/0004-6361/202556432\">10.1051/0004-6361/202556432</a>","ista":"Cristea A-A, Caiazzo I, Cunningham T, Raymond JC, Vennes S, Kawka A, Desai AA, Miller DR, Hermes JJ, Fuller J, Heyl J, van Roestel J, Burdge KB, Rodriguez AC, Pelisoli I, Gänsicke BT, Szkody P, Kenyon SJ, Vanderbosch Z, Drake A, Ferrario L, Wickramasinghe D, Karambelkar VR, Justham S, Pakmor R, El-Badry K, Prince T, Kulkarni SR, Graham MJ, Masci FJ, Groom SL, Purdum J, Dekany R, Bellm EC. 2026. A half ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant. Astronomy &#38; Astrophysics. 706, A188.","apa":"Cristea, A.-A., Caiazzo, I., Cunningham, T., Raymond, J. C., Vennes, S., Kawka, A., … Bellm, E. C. (2026). A half ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202556432\">https://doi.org/10.1051/0004-6361/202556432</a>","ieee":"A.-A. Cristea <i>et al.</i>, “A half ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant,” <i>Astronomy &#38; Astrophysics</i>, vol. 706. EDP Sciences, 2026.","chicago":"Cristea, Andrei-Alexandru, Ilaria Caiazzo, Tim Cunningham, John C. Raymond, Stephane Vennes, Adela Kawka, Aayush A Desai, et al. “A Half Ring of Ionized Circumstellar Material Trapped in the Magnetosphere of a White Dwarf Merger Remnant.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2026. <a href=\"https://doi.org/10.1051/0004-6361/202556432\">https://doi.org/10.1051/0004-6361/202556432</a>."},"department":[{"_id":"IlCa"},{"_id":"GradSch"}],"doi":"10.1051/0004-6361/202556432","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"acknowledgement":"We thank Lynne Hillenbrand and Soumyadeep Bhattacharjee for helpful discussions, and Kishalay De for his help with the WIRC\r\nreduction pipeline. IC was supported by NASA through grants from the Space\r\nTelescope Science Institute, under NASA contracts NASA.22K1813, NAS5-\r\n26555 and NAS5-03127. TC was supported by NASA through the NASA Hubble\r\nFellowship grant HST-HF2-51527.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research\r\nin Astronomy, Inc., for NASA, under contract NAS5-26555. This project has\r\nreceived funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 101020057). This work was based on observations obtained with the\r\nSamuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar\r\nObservatory as part of the Zwicky Transient Facility project. ZTF is supported\r\nby the National Science Foundation under Grants No. AST-1440341, AST2034437, and currently Award #2407588. ZTF receives additional funding from\r\nthe ZTF partnership. Current members include Caltech, USA; Caltech/IPAC,\r\nUSA; University of Maryland, USA; University of California, Berkeley, USA;\r\nUniversity of Wisconsin at Milwaukee, USA; Cornell University, USA; Drexel\r\nUniversity, USA; University of North Carolina at Chapel Hill, USA; Institute\r\nof Science and Technology, Austria; National Central University, Taiwan, and\r\nOKC, University of Stockholm, Sweden. Operations are conducted by Caltech’s\r\nOptical Observatory (COO), Caltech/IPAC, and the University of Washington at\r\nSeattle, USA. This work has made use of data from the European Space Agency\r\n(ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by\r\nthe Gaia Data Processing and Analysis Consortium (DPAC, https://www.\r\ncosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. The Pan-STARRS1 Surveys (PS1)\r\nand the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the PanSTARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck\r\nInstitute for Extraterrestrial Physics, Garching, The Johns Hopkins University,\r\nDurham University, the University of Edinburgh, the Queen’s University Belfast,\r\nthe Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through\r\nthe Planetary Science Division of the NASA Science Mission Directorate, the\r\nNational Science Foundation Grant No. AST–1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory,\r\nand the Gordon and Betty Moore Foundation. This work made use of Astropy\r\n(http://www.astropy.org): a community-developed core Python package\r\nand an ecosystem of tools and resources for astronomy (Astropy Collaboration\r\n2013, 2018, 2022).","day":"10","_id":"21274","file_date_updated":"2026-02-23T12:04:37Z","publication":"Astronomy & Astrophysics","date_published":"2026-02-10T00:00:00Z","publisher":"EDP Sciences","year":"2026","abstract":[{"text":"Many white dwarfs are observed in compact double white dwarf binaries, and through the emission of gravitational waves, a large fraction are destined to merge. The merger remnants that do not explode in a Type Ia supernova are expected to initially be rapidly rotating and highly magnetized. In this work, we present our discovery of the variable white dwarf ZTF J200832.79+444939.67, hereafter ZTF J2008+4449, as a likely merger remnant showing signs of circumstellar material without a stellar or substellar companion. The nature of ZTF J2008+4449 as a merger remnant is supported by its physical properties: it is hot (35 500 ± 300 K) and massive (1.12 ± 0.03 M\r\n                    <jats:sub>⊙</jats:sub>\r\n                    ), rapidly rotating with a period of ≈6.6 minutes, and likely possesses exceptionally strong magnetic fields (∼400−600 MG) at its surface. Remarkably, we detect a significant period derivative of (1.80 ± 0.09)×10\r\n                    <jats:sup>−12</jats:sup>\r\n                    s/s, indicating that the white dwarf is spinning down, and a soft X-ray emission that is inconsistent with photospheric emission. As the presence of a mass-transferring stellar or brown dwarf companion is excluded by infrared photometry, the detected spin-down and X-ray emission could be tell-tale signs of a magnetically driven wind or of interaction with circumstellar material, possibly originating from the fallback of gravitationally bound merger ejecta or from the tidal disruption of a planetary object. We also detect Balmer emission, which requires the presence of ionized hydrogen in the vicinity of the white dwarf, showing Doppler shifts as high as ≈2000 km s\r\n                    <jats:sup>−1</jats:sup>\r\n                    . The unusual variability of the Balmer emission on the spin period of the white dwarf is consistent with the trapping of a half ring of ionized gas in the magnetosphere of the white dwarf.\r\n                  </jats:p>","lang":"eng"}],"date_updated":"2026-04-28T12:01:21Z","month":"02","oa_version":"Published Version","file":[{"file_id":"21350","access_level":"open_access","creator":"dernst","date_created":"2026-02-23T12:04:37Z","relation":"main_file","content_type":"application/pdf","file_name":"2026_AstronomyAstrophysics_Cristea.pdf","checksum":"229b688e6e78cab5bb8e2bac366d1575","file_size":5352853,"date_updated":"2026-02-23T12:04:37Z","success":1}],"publication_status":"published","OA_place":"publisher","article_processing_charge":"Yes","language":[{"iso":"eng"}],"author":[{"id":"4d500bea-31f8-11ee-a48d-d4904fb363c7","last_name":"Cristea","full_name":"Cristea, Andrei-Alexandru","first_name":"Andrei-Alexandru"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","full_name":"Caiazzo, Ilaria","first_name":"Ilaria","orcid":"0000-0002-4770-5388","last_name":"Caiazzo"},{"first_name":"Tim","full_name":"Cunningham, Tim","last_name":"Cunningham"},{"last_name":"Raymond","first_name":"John C.","full_name":"Raymond, John C."},{"first_name":"Stephane","full_name":"Vennes, Stephane","last_name":"Vennes"},{"first_name":"Adela","full_name":"Kawka, Adela","last_name":"Kawka"},{"full_name":"Desai, Aayush A","first_name":"Aayush A","last_name":"Desai","id":"502cfd30-32c1-11ee-a9a4-d8dad5c6739e"},{"last_name":"Miller","full_name":"Miller, David R.","first_name":"David R."},{"full_name":"Hermes, J. J.","first_name":"J. J.","last_name":"Hermes"},{"full_name":"Fuller, Jim","first_name":"Jim","last_name":"Fuller"},{"last_name":"Heyl","full_name":"Heyl, Jeremy","first_name":"Jeremy"},{"first_name":"Jan","full_name":"van Roestel, Jan","last_name":"van Roestel"},{"first_name":"Kevin B.","full_name":"Burdge, Kevin B.","last_name":"Burdge"},{"last_name":"Rodriguez","first_name":"Antonio C.","full_name":"Rodriguez, Antonio C."},{"last_name":"Pelisoli","full_name":"Pelisoli, Ingrid","first_name":"Ingrid"},{"last_name":"Gänsicke","first_name":"Boris T.","full_name":"Gänsicke, Boris T."},{"last_name":"Szkody","first_name":"Paula","full_name":"Szkody, Paula"},{"first_name":"Scott J.","full_name":"Kenyon, Scott J.","last_name":"Kenyon"},{"full_name":"Vanderbosch, Zach","first_name":"Zach","last_name":"Vanderbosch"},{"full_name":"Drake, Andrew","first_name":"Andrew","last_name":"Drake"},{"first_name":"Lilia","full_name":"Ferrario, Lilia","last_name":"Ferrario"},{"full_name":"Wickramasinghe, Dayal","first_name":"Dayal","last_name":"Wickramasinghe"},{"first_name":"Viraj R.","full_name":"Karambelkar, Viraj R.","last_name":"Karambelkar"},{"full_name":"Justham, Stephen","first_name":"Stephen","last_name":"Justham"},{"first_name":"Ruediger","full_name":"Pakmor, Ruediger","last_name":"Pakmor"},{"full_name":"El-Badry, Kareem","first_name":"Kareem","last_name":"El-Badry"},{"first_name":"Thomas","full_name":"Prince, Thomas","last_name":"Prince"},{"first_name":"S. R.","full_name":"Kulkarni, S. R.","last_name":"Kulkarni"},{"full_name":"Graham, Matthew J.","first_name":"Matthew J.","last_name":"Graham"},{"full_name":"Masci, Frank J.","first_name":"Frank J.","last_name":"Masci"},{"first_name":"Steven L.","full_name":"Groom, Steven L.","last_name":"Groom"},{"last_name":"Purdum","full_name":"Purdum, Josiah","first_name":"Josiah"},{"first_name":"Richard","full_name":"Dekany, Richard","last_name":"Dekany"},{"first_name":"Eric C.","full_name":"Bellm, Eric C.","last_name":"Bellm"}],"intvolume":"       706","status":"public","DOAJ_listed":"1","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"quality_controlled":"1","title":"A half ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant","has_accepted_license":"1","OA_type":"gold","volume":706,"related_material":{"link":[{"relation":"press_release","description":"News on ISTA website","url":"https://ista.ac.at/en/news/twos-company-new-class-of-star-remnants/"}]},"article_number":"A188","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","PlanS_conform":"1","corr_author":"1","article_type":"original","date_created":"2026-02-17T08:12:05Z","ddc":["520"]},{"article_number":"237","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","ddc":["520"],"date_created":"2026-04-12T22:01:47Z","article_type":"original","OA_type":"gold","has_accepted_license":"1","volume":1000,"DOAJ_listed":"1","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"title":"An eclipsing 8.56 minutes orbital period mass-transferring binary","quality_controlled":"1","external_id":{"arxiv":["2601.07925"]},"author":[{"last_name":"Chickles","first_name":"Emma T.","full_name":"Chickles, Emma T."},{"last_name":"Chakraborty","full_name":"Chakraborty, Joheen","first_name":"Joheen"},{"last_name":"Burdge","full_name":"Burdge, Kevin B.","first_name":"Kevin B."},{"full_name":"Dhillon, Vik S.","first_name":"Vik S.","last_name":"Dhillon"},{"first_name":"Paul","full_name":"Draghis, Paul","last_name":"Draghis"},{"last_name":"El-Badry","first_name":"Kareem","full_name":"El-Badry, Kareem"},{"last_name":"Green","first_name":"Matthew J.","full_name":"Green, Matthew J."},{"first_name":"Aaron","full_name":"Householder, Aaron","last_name":"Householder"},{"full_name":"Hughes, Sarah","first_name":"Sarah","last_name":"Hughes"},{"full_name":"Layden, Christopher","first_name":"Christopher","last_name":"Layden"},{"full_name":"Littlefair, Stuart P.","first_name":"Stuart P.","last_name":"Littlefair"},{"last_name":"Munday","first_name":"James","full_name":"Munday, James"},{"last_name":"Pelisoli","first_name":"Ingrid","full_name":"Pelisoli, Ingrid"},{"full_name":"Redden, Maya S.","first_name":"Maya S.","last_name":"Redden"},{"first_name":"John","full_name":"Tonry, John","last_name":"Tonry"},{"id":"4d122fc8-6083-11f0-87a5-97d68b860333","full_name":"van Roestel, Joannes C","first_name":"Joannes C","last_name":"van Roestel"},{"last_name":"Angile","full_name":"Angile, Francesco Elio","first_name":"Francesco Elio"},{"last_name":"Brown","first_name":"Alex J.","full_name":"Brown, Alex J."},{"last_name":"Segura","full_name":"Segura, Noel Castro","first_name":"Noel Castro"},{"last_name":"Dinsmore","first_name":"Jack","full_name":"Dinsmore, Jack"},{"full_name":"Dyer, Martin","first_name":"Martin","last_name":"Dyer"},{"last_name":"Furesz","first_name":"Gabor","full_name":"Furesz, Gabor"},{"last_name":"Gabutti","first_name":"Michelle","full_name":"Gabutti, Michelle"},{"last_name":"Garbutt","first_name":"James","full_name":"Garbutt, James"},{"last_name":"García-Mejía","first_name":"Juliana","full_name":"García-Mejía, Juliana"},{"last_name":"Jarvis","first_name":"Daniel","full_name":"Jarvis, Daniel"},{"full_name":"Kennedy, Mark R.","first_name":"Mark R.","last_name":"Kennedy"},{"first_name":"Paul","full_name":"Kerry, Paul","last_name":"Kerry"},{"last_name":"Mccormac","first_name":"James","full_name":"Mccormac, James"},{"last_name":"Mo","full_name":"Mo, Geoffrey","first_name":"Geoffrey"},{"last_name":"Osip","first_name":"Dave","full_name":"Osip, Dave"},{"full_name":"Parsons, Steven","first_name":"Steven","last_name":"Parsons"},{"first_name":"Eleanor","full_name":"Pike, Eleanor","last_name":"Pike"},{"last_name":"Piotrowski","full_name":"Piotrowski, John J.","first_name":"John J."},{"last_name":"Romani","full_name":"Romani, Roger W.","first_name":"Roger W."},{"last_name":"Sahman","first_name":"David","full_name":"Sahman, David"},{"last_name":"Simcoe","first_name":"Rob","full_name":"Simcoe, Rob"}],"language":[{"iso":"eng"}],"status":"public","intvolume":"      1000","file":[{"file_id":"21782","creator":"dernst","access_level":"open_access","relation":"main_file","date_created":"2026-05-04T06:36:00Z","content_type":"application/pdf","checksum":"c8f64a78f36224d8e0ea1f324e43e389","file_name":"2026_AstrophysicalJournal_Chickles.pdf","file_size":1225916,"date_updated":"2026-05-04T06:36:00Z","success":1}],"oa_version":"Published Version","article_processing_charge":"Yes","OA_place":"publisher","publication_status":"published","publisher":"IOP Publishing","date_published":"2026-04-01T00:00:00Z","month":"04","date_updated":"2026-05-04T06:37:12Z","arxiv":1,"year":"2026","scopus_import":"1","abstract":[{"text":"We report the discovery of ATLAS J101342.5−451656.8 (hereafter ATLAS J1013−4516), an 8.56 minute orbital-period mass-transferring AM Canum Venaticorum (AM CVn) binary with a mean Gaia magnitude of G = 19.51, identified via periodic variability in light curves from the Asteroid Terrestrial-impact Last Alert System (ATLAS) of Gaia white dwarf candidates. Follow-up with the Large Lenslet Array Magellan Spectrograph shows a helium-dominated accretion disk, and high-speed ULTRACAM photometry reveals pronounced primary and secondary eclipses. We construct a decade-long timing baseline leveraging light curves from the ATLAS and Gaia surveys, as well as the high-speed imagers ULTRACAM on the New Energy Telescope and proto-Lightspeed on the Magellan Clay telescope. From this timing baseline, we measure an orbital period derivative of P 1.60 0.07 10 = ± × 12 s s−1. Interpreted in the context of stable mass transfer, the magnitude and sign of P indicate that the orbital evolution is governed by the interplay between gravitationalwave-driven angular-momentum losses and mass transfer, directly probing the donor’s structural response to mass loss. We constrain the accretor and donor mass based on stable mass-transfer arguments assuming angularmomentum loss dominated by gravitational-wave emission, allowing us to infer the characteristic gravitational\r\nwave strain of the binary for future space-based GW observatories such as the Laser Interferometer Space Antenna (LISA). We predict a characteristic strain corresponding to a 4 yr LISA signal-to-noise ratio ≳10, establishing ATLAS J1013−4516 as a strong prospective LISA source that will probe long-term orbital evolution in the mass-transferring regime.","lang":"eng"}],"_id":"21705","day":"01","publication":"The Astrophysical Journal","issue":"2","file_date_updated":"2026-05-04T06:36:00Z","department":[{"_id":"IlCa"}],"citation":{"chicago":"Chickles, Emma T., Joheen Chakraborty, Kevin B. Burdge, Vik S. Dhillon, Paul Draghis, Kareem El-Badry, Matthew J. Green, et al. “An Eclipsing 8.56 Minutes Orbital Period Mass-Transferring Binary.” <i>The Astrophysical Journal</i>. IOP Publishing, 2026. <a href=\"https://doi.org/10.3847/1538-4357/ae4871\">https://doi.org/10.3847/1538-4357/ae4871</a>.","ieee":"E. T. Chickles <i>et al.</i>, “An eclipsing 8.56 minutes orbital period mass-transferring binary,” <i>The Astrophysical Journal</i>, vol. 1000, no. 2. IOP Publishing, 2026.","ista":"Chickles ET, Chakraborty J, Burdge KB, Dhillon VS, Draghis P, El-Badry K, Green MJ, Householder A, Hughes S, Layden C, Littlefair SP, Munday J, Pelisoli I, Redden MS, Tonry J, van Roestel JC, Angile FE, Brown AJ, Segura NC, Dinsmore J, Dyer M, Furesz G, Gabutti M, Garbutt J, García-Mejía J, Jarvis D, Kennedy MR, Kerry P, Mccormac J, Mo G, Osip D, Parsons S, Pike E, Piotrowski JJ, Romani RW, Sahman D, Simcoe R. 2026. An eclipsing 8.56 minutes orbital period mass-transferring binary. The Astrophysical Journal. 1000(2), 237.","apa":"Chickles, E. T., Chakraborty, J., Burdge, K. B., Dhillon, V. S., Draghis, P., El-Badry, K., … Simcoe, R. (2026). An eclipsing 8.56 minutes orbital period mass-transferring binary. <i>The Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/ae4871\">https://doi.org/10.3847/1538-4357/ae4871</a>","ama":"Chickles ET, Chakraborty J, Burdge KB, et al. An eclipsing 8.56 minutes orbital period mass-transferring binary. <i>The Astrophysical Journal</i>. 2026;1000(2). doi:<a href=\"https://doi.org/10.3847/1538-4357/ae4871\">10.3847/1538-4357/ae4871</a>","mla":"Chickles, Emma T., et al. “An Eclipsing 8.56 Minutes Orbital Period Mass-Transferring Binary.” <i>The Astrophysical Journal</i>, vol. 1000, no. 2, 237, IOP Publishing, 2026, doi:<a href=\"https://doi.org/10.3847/1538-4357/ae4871\">10.3847/1538-4357/ae4871</a>.","short":"E.T. Chickles, J. Chakraborty, K.B. Burdge, V.S. Dhillon, P. Draghis, K. El-Badry, M.J. Green, A. Householder, S. Hughes, C. Layden, S.P. Littlefair, J. Munday, I. Pelisoli, M.S. Redden, J. Tonry, J.C. van Roestel, F.E. Angile, A.J. Brown, N.C. Segura, J. Dinsmore, M. Dyer, G. Furesz, M. Gabutti, J. Garbutt, J. García-Mejía, D. Jarvis, M.R. Kennedy, P. Kerry, J. Mccormac, G. Mo, D. Osip, S. Parsons, E. Pike, J.J. Piotrowski, R.W. Romani, D. Sahman, R. Simcoe, The Astrophysical Journal 1000 (2026)."},"type":"journal_article","oa":1,"acknowledgement":"This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for near-Earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889 and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen’s University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and the Millennium Institute of Astrophysics (MAS), Chile. VSD and ULTRACAM are supported by STFC grant ST/Z000033/1. J.G.M. gratefully acknowledges support from the Heising-Simons Foundation and the Pappalardo family through the MIT Pappalardo Fellowship in Physics.","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"doi":"10.3847/1538-4357/ae4871"},{"has_accepted_license":"1","OA_type":"gold","volume":548,"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"stag505","article_type":"original","date_created":"2026-04-19T22:07:42Z","ddc":["520"],"language":[{"iso":"eng"}],"external_id":{"arxiv":["2603.12048"]},"author":[{"last_name":"Elms","first_name":"Abbigail K.","full_name":"Elms, Abbigail K."},{"last_name":"Bagnulo","full_name":"Bagnulo, Stefano","first_name":"Stefano"},{"full_name":"Tremblay, Pier Emmanuel","first_name":"Pier Emmanuel","last_name":"Tremblay"},{"last_name":"Cunningham","full_name":"Cunningham, Tim","first_name":"Tim"},{"full_name":"Munday, James","first_name":"James","last_name":"Munday"},{"last_name":"Landstreet","first_name":"John","full_name":"Landstreet, John"},{"full_name":"El-Badry, Kareem","first_name":"Kareem","last_name":"El-Badry"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","first_name":"Ilaria","full_name":"Caiazzo, Ilaria","orcid":"0000-0002-4770-5388","last_name":"Caiazzo"},{"full_name":"Melis, Carl","first_name":"Carl","last_name":"Melis"},{"first_name":"Viktoria","full_name":"Pinter, Viktoria","last_name":"Pinter"},{"last_name":"Weinberger","first_name":"Alycia","full_name":"Weinberger, Alycia"}],"intvolume":"       548","status":"public","DOAJ_listed":"1","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"quality_controlled":"1","title":"Detection of a weak magnetic field in the Balmer emission line white dwarf WDJ1653−1001","date_published":"2026-05-01T00:00:00Z","publisher":"Oxford University Press","year":"2026","scopus_import":"1","abstract":[{"text":"The small DAHe and DAe spectral classes comprise isolated, hydrogen-dominated atmosphere white dwarfs that exhibit variable photometric flux and Balmer line emission. These mysterious systems offer unique insight into the complex interplay between magnetic fields, stellar rotation and atmospheric activity in single white dwarfs. DAHe stars have detectable magnetic fields through Zeeman-split spectral lines, whereas DAe stars lack such splitting. We report the first discovery and characterization of magnetism in the DAe white dwarf WD J165335.21−100116.33 with new time-resolved spectropolarimetry from FORS2. We detect a weak but variable longitudinal magnetic field with values Bz > −9.2 ± 2.4 kG and Bz < −2.2 ± 1.0 kG. Independent ZTF and ATLAS photometry reveal a consistent period of P = 80.3070 ± 0.0007 h. Time-resolved optical spectroscopy obtained with six ground-based instruments demonstrates strong modulation in the strength of the Hα and Hβ Balmer line emission with P = 80.2922 ± 0.0108 h. The photometric flux and Balmer emission strength vary in antiphase, with the strongest magnetic detections coinciding with phases of low photometric flux and strong line emission. These characteristicssupport the theory that a magnetically active, temperature-inverted spot/region is producing an optically thin chromospheric emission region. Comparison with other DAe and DAHe white dwarfsreveals all systems have a strikingly similar antiphase phenomenology, reinforcing the theory that they are subject to a unified physical mechanism. With the detection of a weak magnetic field, we reclassify WD J165335.21−100116.33 as a low-field DAHe white dwarf. ","lang":"eng"}],"date_updated":"2026-05-04T12:11:53Z","arxiv":1,"month":"05","oa_version":"Published Version","file":[{"date_created":"2026-05-04T12:10:40Z","relation":"main_file","access_level":"open_access","creator":"dernst","file_id":"21794","date_updated":"2026-05-04T12:10:40Z","success":1,"file_size":4991495,"file_name":"2026_MNRAS_Elms.pdf","checksum":"75c48d70d10a9a48875f577e04da80bc","content_type":"application/pdf"}],"publication_status":"published","OA_place":"publisher","article_processing_charge":"Yes","oa":1,"citation":{"ista":"Elms AK, Bagnulo S, Tremblay PE, Cunningham T, Munday J, Landstreet J, El-Badry K, Caiazzo I, Melis C, Pinter V, Weinberger A. 2026. Detection of a weak magnetic field in the Balmer emission line white dwarf WDJ1653−1001. Monthly Notices of the Royal Astronomical Society. 548(1), stag505.","apa":"Elms, A. K., Bagnulo, S., Tremblay, P. E., Cunningham, T., Munday, J., Landstreet, J., … Weinberger, A. (2026). Detection of a weak magnetic field in the Balmer emission line white dwarf WDJ1653−1001. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stag505\">https://doi.org/10.1093/mnras/stag505</a>","ama":"Elms AK, Bagnulo S, Tremblay PE, et al. Detection of a weak magnetic field in the Balmer emission line white dwarf WDJ1653−1001. <i>Monthly Notices of the Royal Astronomical Society</i>. 2026;548(1). doi:<a href=\"https://doi.org/10.1093/mnras/stag505\">10.1093/mnras/stag505</a>","mla":"Elms, Abbigail K., et al. “Detection of a Weak Magnetic Field in the Balmer Emission Line White Dwarf WDJ1653−1001.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 548, no. 1, stag505, Oxford University Press, 2026, doi:<a href=\"https://doi.org/10.1093/mnras/stag505\">10.1093/mnras/stag505</a>.","short":"A.K. Elms, S. Bagnulo, P.E. Tremblay, T. Cunningham, J. Munday, J. Landstreet, K. El-Badry, I. Caiazzo, C. Melis, V. Pinter, A. Weinberger, Monthly Notices of the Royal Astronomical Society 548 (2026).","chicago":"Elms, Abbigail K., Stefano Bagnulo, Pier Emmanuel Tremblay, Tim Cunningham, James Munday, John Landstreet, Kareem El-Badry, et al. “Detection of a Weak Magnetic Field in the Balmer Emission Line White Dwarf WDJ1653−1001.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2026. <a href=\"https://doi.org/10.1093/mnras/stag505\">https://doi.org/10.1093/mnras/stag505</a>.","ieee":"A. K. Elms <i>et al.</i>, “Detection of a weak magnetic field in the Balmer emission line white dwarf WDJ1653−1001,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 548, no. 1. Oxford University Press, 2026."},"type":"journal_article","department":[{"_id":"IlCa"}],"doi":"10.1093/mnras/stag505","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"acknowledgement":"This project has received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (Grant agreement numbers 101002408). The observationsfrom the FOcal Reducer/low dispersion Spectrograph 2 (FORS2) instrument were collected at the European Southern Observatory (ESO) under ESO programme(s) 113.26ES.001. This work has made use of data from the European Space\r\nAgency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/conso\r\nrtium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grants No. AST-1440341 and AST-2034437 and a collaboration including current partners Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and\r\nHumboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, IN2P3, University\r\nof Warwick, Ruhr University Bochum, Northwestern University and former partners the University of Washington, Los Alamos National Laboratories, and Lawrence Berkeley National Laboratories. Operations are conducted by COO, IPAC, and UW. This work has made use of data from the Asteroid Terrestrialimpact Last Alert System (ATLAS) project. The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen’s University Belfast, the Space Telescope Science Institute, the South African\r\nAstronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile.\r\nThis work makes use of observations from the Las Cumbres Observatory global telescope network. Research at Lick Observatory is partially supported by a generous gift from Google. A major upgrade of the Kast spectrograph on the Shane 3 m telescope at Lick Observatory was made possible through generous gifts from William and Marina Kast as well as the Heising–Simons Foundation. The Isaac Newton Telescope is operated on the island of La Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile. Observations reported here were obtained at the Multiple Mirror Telescope (MMT) Observatory, a joint facility of the Smithsonian Institution and the University of Arizona. Based on observations collected at Centro Astronómico Hispano en Andalucía (CAHA) at Calar Alto, operated jointly by Junta de Andalucía and Consejo Superior de Investigaciones Científicas (IAA-CSIC).","day":"01","_id":"21745","file_date_updated":"2026-05-04T12:10:40Z","issue":"1","publication":"Monthly Notices of the Royal Astronomical Society"},{"has_accepted_license":"1","OA_type":"gold","volume":547,"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"stag521","article_type":"original","ddc":["520"],"date_created":"2026-05-03T22:01:37Z","author":[{"last_name":"Parsons","full_name":"Parsons, S. G.","first_name":"S. G."},{"first_name":"A. J.","full_name":"Brown, A. J.","last_name":"Brown"},{"last_name":"Casewell","first_name":"S. L.","full_name":"Casewell, S. L."},{"full_name":"Littlefair, S. P.","first_name":"S. P.","last_name":"Littlefair"},{"last_name":"van Roestel","full_name":"van Roestel, Joannes C","first_name":"Joannes C","id":"4d122fc8-6083-11f0-87a5-97d68b860333"},{"full_name":"Rebassa-Mansergas, A.","first_name":"A.","last_name":"Rebassa-Mansergas"},{"last_name":"Murillo-Ojeda","first_name":"R.","full_name":"Murillo-Ojeda, R."},{"full_name":"Zorotovic, M.","first_name":"M.","last_name":"Zorotovic"},{"last_name":"Schreiber","first_name":"M. R.","full_name":"Schreiber, M. R."},{"first_name":"S.","full_name":"Bagnulo, S.","last_name":"Bagnulo"},{"last_name":"Stroet","full_name":"Stroet, M. A.","first_name":"M. A."},{"full_name":"Castro Segura, N.","first_name":"N.","last_name":"Castro Segura"},{"full_name":"Dhillon, V. S.","first_name":"V. S.","last_name":"Dhillon"},{"last_name":"Dyer","full_name":"Dyer, M. J.","first_name":"M. J."},{"first_name":"J. A.","full_name":"Garbutt, J. A.","last_name":"Garbutt"},{"first_name":"M. J.","full_name":"Green, M. J.","last_name":"Green"},{"last_name":"Jarvis","full_name":"Jarvis, D.","first_name":"D."},{"last_name":"Kennedy","first_name":"M. R.","full_name":"Kennedy, M. R."},{"full_name":"Kerry, P.","first_name":"P.","last_name":"Kerry"},{"full_name":"Mccormac, J.","first_name":"J.","last_name":"Mccormac"},{"first_name":"J.","full_name":"Munday, J.","last_name":"Munday"},{"first_name":"I.","full_name":"Pelisoli, I.","last_name":"Pelisoli"},{"last_name":"Pike","first_name":"E.","full_name":"Pike, E."},{"last_name":"Sahman","first_name":"D. I.","full_name":"Sahman, D. I."},{"first_name":"A.","full_name":"Yates, A.","last_name":"Yates"}],"external_id":{"arxiv":["2603.12888"]},"language":[{"iso":"eng"}],"intvolume":"       547","status":"public","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"DOAJ_listed":"1","title":"ZTF J021804.16+071152.93: A dead cataclysmic variable and potential solution to the missing period bouncer cataclysmic variables","quality_controlled":"1","publisher":"Oxford University Press","date_published":"2026-04-01T00:00:00Z","abstract":[{"text":"It is predicted that half or more of all cataclysmic variables (CVs) should have evolved past the period minimum and now exist as so-called period bouncers where a white dwarf should be accreting from a Roche lobe filling substellar companion. However, this prediction stands in stark contrast to observations, where only a few per cent of CVs are found in this evolutionary phase. A potential solution to this discrepancy is that a magnetic field emerges from within the white dwarf after the system has reached the period minimum. The transfer of angular momentum from the spin of the white dwarf into the orbit then pushes the two stars apart, detaching them for potentially billions of years. Here we present the discovery of ZTF J021804.16+071152.93, a detached 0.69 +- 0.01 M⁠, 19 MG magnetic white dwarf plus 37 +- 5MJup brown dwarf binary with an orbital period of 1.7 h. The kinematics of the system indicate that it is a high probability member of the Galactic thick disc. However, this strongly disagrees with the much younger age of the system obtained from the white dwarf parameters, implying that the system may have been accreting in the past. This system is therefore consistent with having detached as a result of the emergence of the magnetic field of the white dwarf when the system was still mass transferring, and may represent the ultimate fate for many (perhaps even most) CVs.","lang":"eng"}],"year":"2026","scopus_import":"1","month":"04","arxiv":1,"date_updated":"2026-05-07T07:51:58Z","oa_version":"Published Version","file":[{"file_id":"21834","date_created":"2026-05-07T07:51:06Z","relation":"main_file","access_level":"open_access","creator":"dernst","file_name":"2026_MNRAS_Parsons.pdf","checksum":"a64094199db4dedb12fc121b7c65fe97","content_type":"application/pdf","date_updated":"2026-05-07T07:51:06Z","success":1,"file_size":5955512}],"OA_place":"publisher","publication_status":"published","article_processing_charge":"Yes","oa":1,"department":[{"_id":"IlCa"}],"type":"journal_article","citation":{"ista":"Parsons SG, Brown AJ, Casewell SL, Littlefair SP, van Roestel JC, Rebassa-Mansergas A, Murillo-Ojeda R, Zorotovic M, Schreiber MR, Bagnulo S, Stroet MA, Castro Segura N, Dhillon VS, Dyer MJ, Garbutt JA, Green MJ, Jarvis D, Kennedy MR, Kerry P, Mccormac J, Munday J, Pelisoli I, Pike E, Sahman DI, Yates A. 2026. ZTF J021804.16+071152.93: A dead cataclysmic variable and potential solution to the missing period bouncer cataclysmic variables. Monthly Notices of the Royal Astronomical Society. 547(4), stag521.","apa":"Parsons, S. G., Brown, A. J., Casewell, S. L., Littlefair, S. P., van Roestel, J. C., Rebassa-Mansergas, A., … Yates, A. (2026). ZTF J021804.16+071152.93: A dead cataclysmic variable and potential solution to the missing period bouncer cataclysmic variables. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stag521\">https://doi.org/10.1093/mnras/stag521</a>","mla":"Parsons, S. G., et al. “ZTF J021804.16+071152.93: A Dead Cataclysmic Variable and Potential Solution to the Missing Period Bouncer Cataclysmic Variables.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 547, no. 4, stag521, Oxford University Press, 2026, doi:<a href=\"https://doi.org/10.1093/mnras/stag521\">10.1093/mnras/stag521</a>.","ama":"Parsons SG, Brown AJ, Casewell SL, et al. ZTF J021804.16+071152.93: A dead cataclysmic variable and potential solution to the missing period bouncer cataclysmic variables. <i>Monthly Notices of the Royal Astronomical Society</i>. 2026;547(4). doi:<a href=\"https://doi.org/10.1093/mnras/stag521\">10.1093/mnras/stag521</a>","short":"S.G. Parsons, A.J. Brown, S.L. Casewell, S.P. Littlefair, J.C. van Roestel, A. Rebassa-Mansergas, R. Murillo-Ojeda, M. Zorotovic, M.R. Schreiber, S. Bagnulo, M.A. Stroet, N. Castro Segura, V.S. Dhillon, M.J. Dyer, J.A. Garbutt, M.J. Green, D. Jarvis, M.R. Kennedy, P. Kerry, J. Mccormac, J. Munday, I. Pelisoli, E. Pike, D.I. Sahman, A. Yates, Monthly Notices of the Royal Astronomical Society 547 (2026).","chicago":"Parsons, S. G., A. J. Brown, S. L. Casewell, S. P. Littlefair, Joannes C van Roestel, A. Rebassa-Mansergas, R. Murillo-Ojeda, et al. “ZTF J021804.16+071152.93: A Dead Cataclysmic Variable and Potential Solution to the Missing Period Bouncer Cataclysmic Variables.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2026. <a href=\"https://doi.org/10.1093/mnras/stag521\">https://doi.org/10.1093/mnras/stag521</a>.","ieee":"S. G. Parsons <i>et al.</i>, “ZTF J021804.16+071152.93: A dead cataclysmic variable and potential solution to the missing period bouncer cataclysmic variables,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 547, no. 4. Oxford University Press, 2026."},"acknowledgement":"The results presented in this paper are based on observations collected at the European Southern Observatory under programme IDs 113.D-0277 and 114.D-0066 and on observations made with the Gran Telescopio Canarias (programme ID GTC119-23B), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma.\r\n\r\nSGP acknowledges support by the Science and Technology Facilities Council (grant ST/B001174/1). ARM acknowledges support from MINECO under the PID2023-148661NB-I00 grant and by the AGAUR/Generalitat de Catalunya grant SGR-386/2021. RMO was funded by INTA through grant PRE-OBSERVATORIO and acknowledges support from project PID2023-146210NB-I00 funded by MICIU/AEI/10.13039/501100011033 and by ERDF/EU. MZ acknowledges support from FONDECYT (grants 1250525 and 1221059). VSD and HiPERCAM were funded by the Science and Technology Facilities Council (grant ST/Z000033/1). MRS thanks for support from FONDECYT (grant No. 1221059). This project received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (Grant agreement numbers 101002408-MOS100PC).","publication_identifier":{"issn":["0035-8711"],"eissn":["1365-2966"]},"doi":"10.1093/mnras/stag521","_id":"21780","day":"01","issue":"4","file_date_updated":"2026-05-07T07:51:06Z","publication":"Monthly Notices of the Royal Astronomical Society"},{"language":[{"iso":"eng"}],"author":[{"first_name":"Jan","full_name":"Kára, Jan","last_name":"Kára"},{"last_name":"Rivera Sandoval","full_name":"Rivera Sandoval, Liliana","first_name":"Liliana"},{"full_name":"Mendoza, Wendy","first_name":"Wendy","last_name":"Mendoza"},{"full_name":"Maccarone, Thomas","first_name":"Thomas","last_name":"Maccarone"},{"full_name":"Pichardo Marcano, Manuel","first_name":"Manuel","last_name":"Pichardo Marcano"},{"first_name":"Luis E.","full_name":"Salazar Manzano, Luis E.","last_name":"Salazar Manzano"},{"last_name":"Oelkers","full_name":"Oelkers, Ryan J.","first_name":"Ryan J."},{"last_name":"van Roestel","first_name":"Joannes C","full_name":"van Roestel, Joannes C","id":"4d122fc8-6083-11f0-87a5-97d68b860333"}],"intvolume":"        43","status":"public","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"quality_controlled":"1","title":"A study of transients from ground-based surveys reveals new ultra-compact accreting white dwarf binaries","has_accepted_license":"1","OA_type":"hybrid","volume":43,"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"e052","PlanS_conform":"1","article_type":"original","date_created":"2026-05-07T08:55:00Z","ddc":["520"],"oa":1,"citation":{"ista":"Kára J, Rivera Sandoval L, Mendoza W, Maccarone T, Pichardo Marcano M, Salazar Manzano LE, Oelkers RJ, van Roestel JC. 2026. A study of transients from ground-based surveys reveals new ultra-compact accreting white dwarf binaries. Publications of the Astronomical Society of Australia. 43, e052.","apa":"Kára, J., Rivera Sandoval, L., Mendoza, W., Maccarone, T., Pichardo Marcano, M., Salazar Manzano, L. E., … van Roestel, J. C. (2026). A study of transients from ground-based surveys reveals new ultra-compact accreting white dwarf binaries. <i>Publications of the Astronomical Society of Australia</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/pasa.2026.10184\">https://doi.org/10.1017/pasa.2026.10184</a>","mla":"Kára, Jan, et al. “A Study of Transients from Ground-Based Surveys Reveals New Ultra-Compact Accreting White Dwarf Binaries.” <i>Publications of the Astronomical Society of Australia</i>, vol. 43, e052, Cambridge University Press, 2026, doi:<a href=\"https://doi.org/10.1017/pasa.2026.10184\">10.1017/pasa.2026.10184</a>.","ama":"Kára J, Rivera Sandoval L, Mendoza W, et al. A study of transients from ground-based surveys reveals new ultra-compact accreting white dwarf binaries. <i>Publications of the Astronomical Society of Australia</i>. 2026;43. doi:<a href=\"https://doi.org/10.1017/pasa.2026.10184\">10.1017/pasa.2026.10184</a>","short":"J. Kára, L. Rivera Sandoval, W. Mendoza, T. Maccarone, M. Pichardo Marcano, L.E. Salazar Manzano, R.J. Oelkers, J.C. van Roestel, Publications of the Astronomical Society of Australia 43 (2026).","chicago":"Kára, Jan, Liliana Rivera Sandoval, Wendy Mendoza, Thomas Maccarone, Manuel Pichardo Marcano, Luis E. Salazar Manzano, Ryan J. Oelkers, and Joannes C van Roestel. “A Study of Transients from Ground-Based Surveys Reveals New Ultra-Compact Accreting White Dwarf Binaries.” <i>Publications of the Astronomical Society of Australia</i>. Cambridge University Press, 2026. <a href=\"https://doi.org/10.1017/pasa.2026.10184\">https://doi.org/10.1017/pasa.2026.10184</a>.","ieee":"J. Kára <i>et al.</i>, “A study of transients from ground-based surveys reveals new ultra-compact accreting white dwarf binaries,” <i>Publications of the Astronomical Society of Australia</i>, vol. 43. Cambridge University Press, 2026."},"type":"journal_article","department":[{"_id":"IlCa"}],"doi":"10.1017/pasa.2026.10184","acknowledgement":"We are grateful to the anonymous referee for providing\r\nus with useful comments and suggestions that improved our manuscript.\r\nJK and LRS acknowledge support from NASA grants NNH22ZDA001N-6152\r\nand 80NSSC24K0638. MPM is partially supported by the Swiss National\r\nScience Foundation IZSTZ0_216537 and by UNAM PAPIIT-IG101224. Based\r\non observations obtained at the international Gemini Observatory, a program\r\nof NSF NOIRLab, which is managed by the Association of Universities for\r\nResearch in Astronomy (AURA) under a cooperative agreement with the U.S.\r\nNational Science Foundation on behalf of the Gemini Observatory partnership:\r\nthe U.S. National Science Foundation (United States), National Research\r\nCouncil (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério\r\nda Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea\r\nAstronomy and Space Science Institute (Republic of Korea). The Gemini\r\ndata were obtained from programs GN-2023B-Q-310 and GS-2024A-Q-311\r\n(PI: Rivera Sandoval) and processed using DRAGONS (Data Reduction for\r\nAstronomy from Gemini Observatory North and South) The Digitized Sky\r\nSurveys were produced at the Space Telescope Science Institute under U.S.\r\nGovernment grant NAG W-2166. The images of these surveys are based on\r\nphotographic data obtained using the Oschin Schmidt Telescope on Palomar\r\nMountain and the UK Schmidt Telescope. The plates were processed into the\r\npresent compressed digital form with the permission of these institutions.\r\nThe National Geographic Society – Palomar Observatory Sky Atlas (POSS-I)\r\nwas made by the California Institute of Technology with grants from the\r\nNational Geographic Society. The Second Palomar Observatory Sky Survey\r\n(POSS-II) was made by the California Institute of Technology with funds\r\nfrom the National Science Foundation, the National Geographic Society, the\r\nSloan Foundation, the Samuel Oschin Foundation, and the Eastman Kodak\r\nCorporation. The Oschin Schmidt Telescope is operated by the California\r\nInstitute of Technology and Palomar Observatory. The UK Schmidt Telescope\r\nwas operated by the Royal Observatory Edinburgh, with funding from the\r\nUK Science and Engineering Research Council (later the UK Particle Physics\r\nand Astronomy Research Council), until 1988 June, and thereafter by the\r\nAnglo-Australian Observatory. The blue plates of the southern Sky Atlas\r\nand its Equatorial Extension (together known as the SERC-J), as well as the\r\nEquatorial Red (ER), and the Second Epoch [red] Survey (SES) were all taken\r\nwith the UK Schmidt. Supplemental funding for sky-survey work at the ST\r\nScI is provided by the European Southern Observatory. Based on observations\r\nobtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope\r\nat the Palomar Observatory as part of the Zwicky Transient Facility project.\r\nZTF is supported by the National Science Foundation under Grants No. AST-\r\n1440341 and AST-2034437 and a collaboration including current partners\r\nCaltech, IPAC, the Oskar Klein Center at Stockholm University, the University\r\nof Maryland, University of California, Berkeley, the University of Wisconsin\r\nat Milwaukee, University of Warwick, Ruhr University, Cornell University,\r\nNorthwestern University, and Drexel University. Operations are conducted\r\nby COO, IPAC, and UW. This work has used data from the European\r\nSpace Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia),\r\nprocessed by the Gaia Data Processing and Analysis Consortium (DPAC,\r\nhttps://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the\r\nDPAC has been provided by national institutions, in particular, the institutions\r\nparticipating in the Gaia Multilateral Agreement. We acknowledge with\r\nthanks the variable star observations from the AAVSO International Database\r\ncontributed by observers worldwide and used in this research. This paper\r\nincludes data collected by the TESS mission. Funding for the TESS mission\r\nis provided by the NASA Science Mission Directorate. Some of the data\r\npresented in this paper were obtained from the B. Mikulski Archive for Space\r\nTelescopes (MAST). This research has made use of the SIMBAD database,\r\noperated at CDS, Strasbourg, France. This research has made use of ‘Aladin\r\nsky atlas’ developed at CDS, Strasbourg Observatory, France. This research\r\nhas made use of the VizieR catalogue access tool, CDS, Strasbourg, France.","publication_identifier":{"issn":["1323-3580"],"eissn":["1448-6083"]},"_id":"21842","day":"27","file_date_updated":"2026-05-12T06:54:10Z","publication":"Publications of the Astronomical Society of Australia","date_published":"2026-03-27T00:00:00Z","publisher":"Cambridge University Press","scopus_import":"1","abstract":[{"text":"AM CVn stars are ultra-compact semi-detached binaries consisting of a white dwarf primary and a hydrogen-depleted secondary. In this\r\npaper, we present spectroscopic and photometric results of 15 transient sources pre-classified as AM CVn candidates. Our analysis confirms\r\n9 systems of the type AM CVn, 3 hydrogen-rich cataclysmic variables (accreting white dwarfs with near-main-sequence stars for donors),\r\nand 3 systems that could be evolved cataclysmic variables. Eight of the AM CVn stars are analysed spectroscopically for the first time,\r\nwhich increases the number of spectroscopically confirmed AM CVns by about 10%. TESS data revealed the orbital period of the AM CVn\r\nstar ASASSN-20pv to be Porb =27.282 min, which helps to constrain the possible values of its mass ratio. TESS also helped to determine\r\nthe superhump periods of one AM CVn star (ASASSN-19ct, Psh =30.94 min) and two cataclysmic variables we classify as WZ Sge stars\r\n(Psh =90.77 min for ZTF18aaaasnn and Psh =91.6min for ASASSN-15na).We identified very different abundances in the spectra of theAM\r\nCVns binaries ASASSN-15kf and ASASSN-20pv (both Porb ∼27.5min), suggesting different type of donors. Six of the studied AMCVns are\r\nX-ray sources, which helped to determine their mass accretion rates. Photometry shows that the duration of all the superoutbursts detected\r\nin the AM CVns is consistent with expectations from the disc instability model. Finally, we provide refined criteria for the identification of\r\nnew systems using all-sky surveys such as LSST.","lang":"eng"}],"year":"2026","date_updated":"2026-05-12T06:57:40Z","month":"03","oa_version":"Published Version","file":[{"file_id":"21862","date_created":"2026-05-12T06:54:10Z","relation":"main_file","access_level":"open_access","creator":"dernst","file_name":"2026_PublAstronomicalSocAustralia_Kara.pdf","checksum":"f8f3cd3765948e8b276176c71c9d4e02","content_type":"application/pdf","date_updated":"2026-05-12T06:54:10Z","success":1,"file_size":3681016}],"OA_place":"publisher","publication_status":"published","article_processing_charge":"Yes (in subscription journal)"},{"title":"No period change in two long-period AM CVn binaries","quality_controlled":"1","DOAJ_listed":"1","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"intvolume":"       548","status":"public","author":[{"first_name":"Matthew J","full_name":"Green, Matthew J","last_name":"Green"},{"last_name":"Marsh","first_name":"Thomas R","full_name":"Marsh, Thomas R"},{"id":"4d122fc8-6083-11f0-87a5-97d68b860333","full_name":"van Roestel, Joannes C","first_name":"Joannes C","last_name":"van Roestel"},{"first_name":"Tin Long Sunny","full_name":"Wong, Tin Long Sunny","last_name":"Wong"},{"last_name":"Belloni","first_name":"Diogo","full_name":"Belloni, Diogo"},{"first_name":"Mukremin","full_name":"Kilic, Mukremin","last_name":"Kilic"},{"first_name":"Elmé","full_name":"Breedt, Elmé","last_name":"Breedt"},{"first_name":"Alex","full_name":"Brown, Alex","last_name":"Brown"},{"full_name":"Copperwheat, Chris M","first_name":"Chris M","last_name":"Copperwheat"},{"first_name":"Anurak","full_name":"Chakpor, Anurak","last_name":"Chakpor"},{"full_name":"Dhillon, V S","first_name":"V S","last_name":"Dhillon"},{"last_name":"Segura","first_name":"Noel Castro","full_name":"Segura, Noel Castro"},{"last_name":"Dyer","first_name":"Martin J","full_name":"Dyer, Martin J"},{"full_name":"Garbutt, James","first_name":"James","last_name":"Garbutt"},{"full_name":"Jarvis, Dan","first_name":"Dan","last_name":"Jarvis"},{"full_name":"Kengkriangkrai, Vasu","first_name":"Vasu","last_name":"Kengkriangkrai"},{"first_name":"Mark R","full_name":"Kennedy, Mark R","last_name":"Kennedy"},{"first_name":"Paul","full_name":"Kerry, Paul","last_name":"Kerry"},{"first_name":"Thomas","full_name":"Kupfer, Thomas","last_name":"Kupfer"},{"last_name":"Littlefair","first_name":"S P","full_name":"Littlefair, S P"},{"full_name":"McCormac, James","first_name":"James","last_name":"McCormac"},{"full_name":"Munday, James","first_name":"James","last_name":"Munday"},{"last_name":"Parsons","full_name":"Parsons, Steven G","first_name":"Steven G"},{"last_name":"Pike","first_name":"Eleanor","full_name":"Pike, Eleanor"},{"last_name":"Pelisoli","first_name":"Ingrid","full_name":"Pelisoli, Ingrid"},{"last_name":"Rodríguez-Gil","first_name":"Pablo","full_name":"Rodríguez-Gil, Pablo"},{"last_name":"Sahman","full_name":"Sahman, David I","first_name":"David I"},{"first_name":"Amalie","full_name":"Yates, Amalie","last_name":"Yates"}],"external_id":{"arxiv":["2604.06460"]},"language":[{"iso":"eng"}],"article_type":"original","ddc":["520"],"date_created":"2026-05-20T14:34:03Z","PlanS_conform":"1","keyword":["binaries: close – stars","dwarf novae – novae","cataclysmic variables – white dwarfs"],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"stag673","volume":548,"has_accepted_license":"1","OA_type":"gold","issue":"3","file_date_updated":"2026-05-21T06:37:42Z","publication":"Monthly Notices of the Royal Astronomical Society","_id":"21897","day":"09","acknowledgement":"We are grateful to the anonymousreferee fortheirinsightful comments. MJG thanks Mitch Begelman and the JILA department at the University of Colorado, Boulder, for providing office space at which much of this paper was written. This work is supported in part by the United States National Aeronautics and Space Administration (NASA) under grants\r\n80NSSC24K0436, 80NSSC22K0479, and 80NSSC24K0380, and the United States National Science Foundation (NSF) under grant AST-2508429. VSD and HiPERCAM are funded by the Science and Technology Facilities Council (grant ST/Z000033/1). IP acknowledges support from the Royal Society through a University Research Fellowship (URF\\R1\\231496). This project has received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (grant agreement numbers 101002408 – MOS100PC). CMC receives funding from United Kingdom Research and Innovation grant numbers ST/X005933/1 and ST/W001934/1. This article is based in part on observations made in the Observatorios de Canarias del Instituto de Astrofísica de Canarias (IAC) with the the William Herschel Telescope (WHT) operated on the island of La Palma by the Isaac Newton Group (ING) in the Observatorio del Roque de los Muchachos. It is also based in part on observations made with the Gran Telescopio Canarias (GTC) under proposal ID GTC18-24A, installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, in the island of La Palma. Further data were obtained using the 2.4 m Thai National Telescope (TNT) operated by the National Astronomy Research Institute of Thailand\r\n(NARIT), and the 200-inch Hale Telescope at Palomar Observatory operated by the California Institute of Technology. Software packages used in this work include the ultracam and hipercam reduction pipelines, lcurve (C. M. Copperwheat et al. 2010), numpy, astropy, matplotlib, and emcee (D. Foreman-Mackey et al. 2013).","publication_identifier":{"eissn":["1365-2966"],"issn":["0035-8711"]},"doi":"10.1093/mnras/stag673","oa":1,"type":"journal_article","department":[{"_id":"IlCa"}],"citation":{"apa":"Green, M. J., Marsh, T. R., van Roestel, J. C., Wong, T. L. S., Belloni, D., Kilic, M., … Yates, A. (2026). No period change in two long-period AM CVn binaries. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/stag673\">https://doi.org/10.1093/mnras/stag673</a>","ista":"Green MJ, Marsh TR, van Roestel JC, Wong TLS, Belloni D, Kilic M, Breedt E, Brown A, Copperwheat CM, Chakpor A, Dhillon VS, Segura NC, Dyer MJ, Garbutt J, Jarvis D, Kengkriangkrai V, Kennedy MR, Kerry P, Kupfer T, Littlefair SP, McCormac J, Munday J, Parsons SG, Pike E, Pelisoli I, Rodríguez-Gil P, Sahman DI, Yates A. 2026. No period change in two long-period AM CVn binaries. Monthly Notices of the Royal Astronomical Society. 548(3), stag673.","short":"M.J. Green, T.R. Marsh, J.C. van Roestel, T.L.S. Wong, D. Belloni, M. Kilic, E. Breedt, A. Brown, C.M. Copperwheat, A. Chakpor, V.S. Dhillon, N.C. Segura, M.J. Dyer, J. Garbutt, D. Jarvis, V. Kengkriangkrai, M.R. Kennedy, P. Kerry, T. Kupfer, S.P. Littlefair, J. McCormac, J. Munday, S.G. Parsons, E. Pike, I. Pelisoli, P. Rodríguez-Gil, D.I. Sahman, A. Yates, Monthly Notices of the Royal Astronomical Society 548 (2026).","mla":"Green, Matthew J., et al. “No Period Change in Two Long-Period AM CVn Binaries.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 548, no. 3, stag673, Oxford University Press, 2026, doi:<a href=\"https://doi.org/10.1093/mnras/stag673\">10.1093/mnras/stag673</a>.","ama":"Green MJ, Marsh TR, van Roestel JC, et al. No period change in two long-period AM CVn binaries. <i>Monthly Notices of the Royal Astronomical Society</i>. 2026;548(3). doi:<a href=\"https://doi.org/10.1093/mnras/stag673\">10.1093/mnras/stag673</a>","chicago":"Green, Matthew J, Thomas R Marsh, Joannes C van Roestel, Tin Long Sunny Wong, Diogo Belloni, Mukremin Kilic, Elmé Breedt, et al. “No Period Change in Two Long-Period AM CVn Binaries.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2026. <a href=\"https://doi.org/10.1093/mnras/stag673\">https://doi.org/10.1093/mnras/stag673</a>.","ieee":"M. J. Green <i>et al.</i>, “No period change in two long-period AM CVn binaries,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 548, no. 3. Oxford University Press, 2026."},"OA_place":"publisher","publication_status":"published","article_processing_charge":"Yes","file":[{"file_size":3960296,"success":1,"date_updated":"2026-05-21T06:37:42Z","content_type":"application/pdf","file_name":"2026_MNRAS_Green.pdf","checksum":"2c4463926c5cb84ce555ef2005b52ddd","access_level":"open_access","creator":"dernst","date_created":"2026-05-21T06:37:42Z","relation":"main_file","file_id":"21903"}],"oa_version":"Published Version","scopus_import":"1","year":"2026","abstract":[{"text":"Ultracompact binary systems, consisting of two compact objects in an orbit $\\lesssim 0.5 {\\rm R}_\\odot$, should exhibit measurable rates of orbital period change ($\\dot{P} \\ne 0$) due to the emission of gravitational waves (GWs). Measurements of $\\dot{P}$ have so far been limited to the shortest-period ultracompact binaries ($\\lesssim 20$  min). Among the AM CVn-type subclass, several works have proposed the presence of extra angular momentum loss beyond GW emission, with magnetic braking being a widely discussed mechanism. If present, this magnetic braking would dominate the angular momentum loss of AM CVn-type binaries with orbital periods $\\gtrsim 30$ min. In this work, we present a long-term eclipse timing study of two AM CVn-type binaries, YZ LMi and Gaia14aae, with respective orbital periods of 28.3 min and 49.7 min and continuous observations since 2006 and 2015. Both systems show $\\dot{P}$ consistent with zero within $2\\sigma$. Their $3\\sigma$ upper limits are $1.1 \\times 10^{-13}\\, {\\rm s \\, s}^{-1}$ and $9.7 \\times 10^{-14}\\, {\\rm s \\, s}^{-1}$, respectively. These non-detections are most simply explained by a scenario in which secular angular momentum loss is not substantially stronger than GW emission at all orbital periods, but is combined with deviations from the secular $\\dot{P}$ whose time-scales span decades but whose amplitude is $\\lesssim 10^{-13}\\, {\\rm s \\, s}^{-1}$. Our non-detections of $\\dot{P}$ represent a limit on the strength of any enhanced angular momentum loss beyond pure GW emission.","lang":"eng"}],"month":"04","date_updated":"2026-05-21T06:41:41Z","arxiv":1,"publisher":"Oxford University Press","date_published":"2026-04-09T00:00:00Z"},{"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","ddc":["520"],"date_created":"2025-06-15T22:01:29Z","article_type":"original","OA_type":"gold","has_accepted_license":"1","volume":540,"page":"633-649","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"title":"Discovery of two new polars evolved past the period bounce","quality_controlled":"1","external_id":{"arxiv":["2503.12675"],"isi":["001493143700001"]},"author":[{"last_name":"Cunningham","first_name":"Tim","full_name":"Cunningham, Tim"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","first_name":"Ilaria","full_name":"Caiazzo, Ilaria","last_name":"Caiazzo","orcid":"0000-0002-4770-5388"},{"last_name":"Sienkiewicz","full_name":"Sienkiewicz, Gracjan","first_name":"Gracjan"},{"full_name":"Wheatley, Peter J.","first_name":"Peter J.","last_name":"Wheatley"},{"last_name":"Gänsicke","first_name":"Boris T.","full_name":"Gänsicke, Boris T."},{"first_name":"Kareem","full_name":"El-Badry, Kareem","last_name":"El-Badry"},{"full_name":"Arcodia, Riccardo","first_name":"Riccardo","last_name":"Arcodia"},{"full_name":"Charbonneau, David","first_name":"David","last_name":"Charbonneau"},{"full_name":"Connor, Liam","first_name":"Liam","last_name":"Connor"},{"last_name":"De","first_name":"Kishalay","full_name":"De, Kishalay"},{"last_name":"Hakala","full_name":"Hakala, Pasi","first_name":"Pasi"},{"first_name":"Scott J.","full_name":"Kenyon, Scott J.","last_name":"Kenyon"},{"full_name":"Maheshwari, Sumit Kumar","first_name":"Sumit Kumar","last_name":"Maheshwari"},{"last_name":"Rodriguez","full_name":"Rodriguez, Antonio C.","first_name":"Antonio C."},{"last_name":"Van Roestel","full_name":"Van Roestel, Jan","first_name":"Jan"},{"first_name":"Pier Emmanuel","full_name":"Tremblay, Pier Emmanuel","last_name":"Tremblay"}],"language":[{"iso":"eng"}],"status":"public","intvolume":"       540","oa_version":"Published Version","file":[{"file_size":3212636,"date_updated":"2025-06-23T07:28:36Z","success":1,"content_type":"application/pdf","checksum":"5e675d3696c222e919d6916bad194b01","file_name":"2025_MonthlyNoticesRAS_Cunningham.pdf","creator":"dernst","access_level":"open_access","relation":"main_file","date_created":"2025-06-23T07:28:36Z","file_id":"19864"}],"article_processing_charge":"Yes","OA_place":"publisher","publication_status":"published","publisher":"Oxford University Press","date_published":"2025-06-01T00:00:00Z","isi":1,"month":"06","arxiv":1,"date_updated":"2025-09-30T12:50:33Z","scopus_import":"1","year":"2025","abstract":[{"lang":"eng","text":"We report the discovery of two new magnetic cataclysmic variables with brown dwarf companions and long orbital periods (P_{\\rm orb}=95\\pm1 and 104\\pm2 min). This discovery increases the sample of candidate magnetic period bouncers with confirmed sub-stellar donors from four to six. We also find their X-ray luminosity from archival XMM–Newton observations to be in the range L_{\\rm X}\\approx10^{28}-10^{29} \\mathrm{erg\\,s^{-1}} in the 0.25–10 keV band. This low luminosity is comparable with the other candidates, and at least an order of magnitude lower than the X-ray luminosities typically measured in cataclysmic variables. The X-ray fluxes imply mass transfer rates that are much lower than predicted by evolutionary models, even if some of the discrepancy is due to the accretion energy being emitted in other bands, such as via cyclotron emission at infrared wavelengths. Although it is possible that some or all of these systems formed directly as binaries containing a brown dwarf, it is likely that the donor used to be a low-mass star and that the systems followed the evolutionary track for cataclysmic variables, evolving past the period bounce. The donor in long period systems is expected to be a low-mass, cold brown dwarf. This hypothesis is supported by near-infrared photometric observations that constrain the donors in the two systems to be brown dwarfs cooler than \r\n1100 K (spectral types T5 or later), most likely losing mass via Roche Lobe overflow or winds. The serendipitous discovery of two magnetic period bouncers in the small footprint of the XMM–Newton catalogue implies a large space density of these type of systems, possibly compatible with the prediction of 40–70 per cent of magnetic cataclysmic variables to be period bouncers."}],"day":"01","_id":"19840","publication":"Monthly Notices of the Royal Astronomical Society","issue":"1","file_date_updated":"2025-06-23T07:28:36Z","department":[{"_id":"IlCa"}],"type":"journal_article","citation":{"apa":"Cunningham, T., Caiazzo, I., Sienkiewicz, G., Wheatley, P. J., Gänsicke, B. T., El-Badry, K., … Tremblay, P. E. (2025). Discovery of two new polars evolved past the period bounce. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href=\"https://doi.org/10.1093/mnras/staf561\">https://doi.org/10.1093/mnras/staf561</a>","ista":"Cunningham T, Caiazzo I, Sienkiewicz G, Wheatley PJ, Gänsicke BT, El-Badry K, Arcodia R, Charbonneau D, Connor L, De K, Hakala P, Kenyon SJ, Maheshwari SK, Rodriguez AC, Van Roestel J, Tremblay PE. 2025. Discovery of two new polars evolved past the period bounce. Monthly Notices of the Royal Astronomical Society. 540(1), 633–649.","mla":"Cunningham, Tim, et al. “Discovery of Two New Polars Evolved Past the Period Bounce.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 540, no. 1, Oxford University Press, 2025, pp. 633–49, doi:<a href=\"https://doi.org/10.1093/mnras/staf561\">10.1093/mnras/staf561</a>.","ama":"Cunningham T, Caiazzo I, Sienkiewicz G, et al. Discovery of two new polars evolved past the period bounce. <i>Monthly Notices of the Royal Astronomical Society</i>. 2025;540(1):633-649. doi:<a href=\"https://doi.org/10.1093/mnras/staf561\">10.1093/mnras/staf561</a>","short":"T. Cunningham, I. Caiazzo, G. Sienkiewicz, P.J. Wheatley, B.T. Gänsicke, K. El-Badry, R. Arcodia, D. Charbonneau, L. Connor, K. De, P. Hakala, S.J. Kenyon, S.K. Maheshwari, A.C. Rodriguez, J. Van Roestel, P.E. Tremblay, Monthly Notices of the Royal Astronomical Society 540 (2025) 633–649.","chicago":"Cunningham, Tim, Ilaria Caiazzo, Gracjan Sienkiewicz, Peter J. Wheatley, Boris T. Gänsicke, Kareem El-Badry, Riccardo Arcodia, et al. “Discovery of Two New Polars Evolved Past the Period Bounce.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2025. <a href=\"https://doi.org/10.1093/mnras/staf561\">https://doi.org/10.1093/mnras/staf561</a>.","ieee":"T. Cunningham <i>et al.</i>, “Discovery of two new polars evolved past the period bounce,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 540, no. 1. Oxford University Press, pp. 633–649, 2025."},"oa":1,"publication_identifier":{"eissn":["1365-2966"],"issn":["0035-8711"]},"acknowledgement":"We thank Matthias Schreiber for his insightful comments. Support for this work was provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51527.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. Support for this work was provided by NASA through Chandra Award Number GO4-25014X issued by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060. IC was also supported by NASA through grants from the Space Telescope Science Institute, under NASA contracts NASA.22K1813, NAS5-26555, and NAS5-03127. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 101020057). This research was supported in part by grant NSF PHY-1748958 to the Kavli Institute for Theoretical Physics (KITP). PJW acknowledges support from the UK Science and Technology Facilities Council (STFC) through consolidated grants ST/T000406/1 and ST/X001121/1. RA was supported by NASA through the NASA Hubble Fellowship grant #HST-HF2-51499.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.\r\n\r\nThis research has made use of data obtained from the 4XMM XMM–Newton Serendipitous Source Catalogue compiled by the 10 institutes of the XMM–Newton Survey Science Centre selected by ESA. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen’s University Belfast, the Harvard–Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under grant no. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation grant no. AST–1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. This work is based in part on data obtained as part of the UKIDSS. This research made use of hips2fits,4 a service provided by CDS, and of astropy (Astropy Collaboration 2013).","doi":"10.1093/mnras/staf561"},{"article_type":"original","ddc":["520"],"date_created":"2025-07-06T22:01:22Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"47","volume":170,"has_accepted_license":"1","OA_type":"gold","title":"A candidate giant planet companion to the massive, young White Dwarf GALEX J071816.4+373139 informs the occurrence of giant planets orbiting B stars","quality_controlled":"1","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"DOAJ_listed":"1","intvolume":"       170","status":"public","external_id":{"arxiv":["2408.03985"],"isi":["001514518100001"]},"author":[{"last_name":"Cheng","first_name":"Sihao","full_name":"Cheng, Sihao"},{"first_name":"Kevin C.","full_name":"Schlaufman, Kevin C.","last_name":"Schlaufman"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","last_name":"Caiazzo","orcid":"0000-0002-4770-5388","full_name":"Caiazzo, Ilaria","first_name":"Ilaria"}],"language":[{"iso":"eng"}],"publication_status":"published","OA_place":"publisher","article_processing_charge":"Yes","oa_version":"Published Version","file":[{"content_type":"application/pdf","checksum":"144b0e46aa3dff0cdf8c6ee7d4fe2fe4","file_name":"2025_AstronomicalJour_Cheng.pdf","file_size":931173,"success":1,"date_updated":"2025-07-08T06:40:54Z","file_id":"19975","creator":"dernst","access_level":"open_access","relation":"main_file","date_created":"2025-07-08T06:40:54Z"}],"scopus_import":"1","abstract":[{"lang":"eng","text":"It has been suggested that giant planet occurrence peaks for stars with M* ≈ 3 M⊙ at a value a factor of 4 higher than observed for solar-mass stars. This population of giant planets predicted to frequently orbit main-sequence B stars at a ≈ 10 au is difficult to characterize during the few hundred million years while fusion persists in their host stars. By the time those stars become massive, young white dwarfs, any giant planets present would still be luminous as a consequence of their recent formation. From an initial sample of 2195 Gaia-identified massive, young white dwarfs, we use homogeneous Spitzer Infrared Array Camera (IRAC) photometry to search for evidence of unresolved giant planets. For 30 systems, these IRAC data provide sensitivity to objects with M ≲ 10 MJup, and we identify one candidate with M ≈ 4 MJup orbiting the white dwarf GALEX J071816.4+373139. Correcting for the possibility that some of the white dwarfs in our sample result from mergers, we find a giant planet occurrence  n GP = 0.11+0.13-0.07 for stars with initial masses M* ≳ 3 M⊙. Our occurrence inference is consistent with both the Doppler-inferred occurrence of giant planets orbiting M* ≈ 2 M⊙ giant stars and the theoretically predicted factor of 4 enhancement in the occurrence of giant planets orbiting M* ≈ 3 M⊙ stars relative to solar-mass stars. Future James Webb Space Telescope NIRCam observations of our sample would provide sensitivity to Saturn-mass planets and thereby a definitive estimate of the occurrence of giant planets orbiting stars with M* ≳ 3 M⊙."}],"year":"2025","isi":1,"month":"07","arxiv":1,"date_updated":"2026-02-19T09:31:41Z","publisher":"IOP Publishing","date_published":"2025-07-01T00:00:00Z","issue":"1","file_date_updated":"2025-07-08T06:40:54Z","publication":"The Astronomical Journal","day":"01","_id":"19964","publication_identifier":{"issn":["0004-6256"],"eissn":["1538-3881"]},"acknowledgement":"We thank Jay Farihi, Guangwei Fu, J. J. Hermes, Mary Anne Limbach, and Daniel Thorngren for useful discussions. S.C. thanks Siyu Yao for her constant inspiration and encouragement. S.C. acknowledges the support of the Martin A. and Helen Chooljian Member Fund, funding from the Zurich Insurance Company, and the Fund for Natural Sciences at the Institute for Advanced Study. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This research has made use of NASA’s Astrophysics Data System.\r\nFacilities: ADS - , ESO:VISTA - European Southern Observatory's 4.1 meter Visible and Infrared Survey Telescope for Astronomy, Exoplanet Archive - , Gaia - , IRSA - , NEOWISE - , Spitzer - Spitzer Space Telescope satellite, UKIRT - United Kingdom Infrared Telescope, WISE - Wide-field Infrared Survey Explorer.\r\nSoftware: astropy (Astropy Collaboration et al. 2013, 2018, 2022), numpy (C. R. Harris et al. 2020), matplotlib (J. D. Hunter 2007), R (R Core Team 2024), SciPy (P. Virtanen et al. 2020).","doi":"10.3847/1538-3881/addd21","oa":1,"citation":{"ista":"Cheng S, Schlaufman KC, Caiazzo I. 2025. A candidate giant planet companion to the massive, young White Dwarf GALEX J071816.4+373139 informs the occurrence of giant planets orbiting B stars. The Astronomical Journal. 170(1), 47.","apa":"Cheng, S., Schlaufman, K. C., &#38; Caiazzo, I. (2025). A candidate giant planet companion to the massive, young White Dwarf GALEX J071816.4+373139 informs the occurrence of giant planets orbiting B stars. <i>The Astronomical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-3881/addd21\">https://doi.org/10.3847/1538-3881/addd21</a>","ama":"Cheng S, Schlaufman KC, Caiazzo I. A candidate giant planet companion to the massive, young White Dwarf GALEX J071816.4+373139 informs the occurrence of giant planets orbiting B stars. <i>The Astronomical Journal</i>. 2025;170(1). doi:<a href=\"https://doi.org/10.3847/1538-3881/addd21\">10.3847/1538-3881/addd21</a>","mla":"Cheng, Sihao, et al. “A Candidate Giant Planet Companion to the Massive, Young White Dwarf GALEX J071816.4+373139 Informs the Occurrence of Giant Planets Orbiting B Stars.” <i>The Astronomical Journal</i>, vol. 170, no. 1, 47, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.3847/1538-3881/addd21\">10.3847/1538-3881/addd21</a>.","short":"S. Cheng, K.C. Schlaufman, I. Caiazzo, The Astronomical Journal 170 (2025).","chicago":"Cheng, Sihao, Kevin C. Schlaufman, and Ilaria Caiazzo. “A Candidate Giant Planet Companion to the Massive, Young White Dwarf GALEX J071816.4+373139 Informs the Occurrence of Giant Planets Orbiting B Stars.” <i>The Astronomical Journal</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.3847/1538-3881/addd21\">https://doi.org/10.3847/1538-3881/addd21</a>.","ieee":"S. Cheng, K. C. Schlaufman, and I. Caiazzo, “A candidate giant planet companion to the massive, young White Dwarf GALEX J071816.4+373139 informs the occurrence of giant planets orbiting B stars,” <i>The Astronomical Journal</i>, vol. 170, no. 1. IOP Publishing, 2025."},"department":[{"_id":"IlCa"}],"type":"journal_article"},{"OA_place":"publisher","publication_status":"published","article_processing_charge":"Yes","oa_version":"Published Version","file":[{"content_type":"application/pdf","checksum":"24892d1b5bfa1867eb0a353f10c31b82","file_name":"2025_AstrophysicalJour_Guidry.pdf","file_size":5323398,"success":1,"date_updated":"2025-11-04T12:33:51Z","file_id":"20601","creator":"dernst","access_level":"open_access","relation":"main_file","date_created":"2025-11-04T12:33:51Z"}],"year":"2025","scopus_import":"1","abstract":[{"lang":"eng","text":"We present the discovery of deep, irregular, periodic transits toward the white dwarf ZTF J1944+4557 using follow-up time-series photometry and spectroscopy from Palomar, Keck, McDonald, Perkins, and Lowell observatories. We find a predominant period of 4.9704 hr, consistent with an orbit near the Roche limit of the white dwarf, with individual dips over 30% deep and lasting between 15 and 40 minutes. Similar to the first known white dwarf with transiting debris, WD 1145+017, the transit events are well-defined with prominent out-of-transit phases where the white dwarf appears unobscured. Spectroscopy concurrent with transit photometry reveals that the average Ca K equivalent width remains constant in and out of transit. The broadening observed in several absorption features cannot be reproduced by synthetic photospheric models, suggesting the presence of circumstellar gas. Simultaneous g + r- and g + i-band light curves from the CHIMERA instrument reveal no color dependence to the transit depths, requiring transiting dust grains to have sizes s ≳  0.2 μm. The transit morphologies appear to be constantly changing at a rate faster than the orbital period. Overall transit activity varies in the system, with transit features completely disappearing during the seven months between our 2023 and 2024 observing seasons and then reappearing in 2025 March, still repeating at 4.9704 hr. Our observations of the complete cessation and resumption of transit activity provide a novel laboratory for constraining the evolution of disrupted debris and processes like disk exhaustion and replenishment timescales at white dwarfs."}],"date_updated":"2026-02-16T12:43:29Z","arxiv":1,"month":"10","isi":1,"date_published":"2025-10-20T00:00:00Z","publisher":"IOP Publishing","file_date_updated":"2025-11-04T12:33:51Z","issue":"2","publication":"The Astrophysical Journal","_id":"20586","day":"20","doi":"10.3847/1538-4357/adfecb","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"acknowledgement":"We first extend our gratitude to our anonymous referee, whose careful review and recommendations enhanced this manuscript. In fruitful conversations and correspondence with Tim Cunningham, Jay Farihi, Jim Fuller, Philip Muirhead, Saul Rappaport, Siyi Xu (许偲艺), and Nadia Zakamska, we found guidance that improved our interpretation of these results. We are deeply grateful for the observing support by John Kuehne at McDonald Observatory and Colt Pauley at the Perkins Telescope Observatory. This material is based upon work supported by the National Aeronautics and Space Administration under grant No. 80NSSC23K1068 issued through the Science Mission Directorate. J.A.G. is supported by the National Science Foundation Graduate Research Fellowship Program under grant No. 2234657.\r\n\r\nThis worked is based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under grants No. AST-1440341 and AST-2034437 and a collaboration including current partners Caltech, IPAC, the Oskar Klein Center at Stockholm University, the University of Maryland, University of California, Berkeley, the University of Wisconsin at Milwaukee, University of Warwick, Ruhr University, Cornell University, Northwestern University and Drexel University. Operations are conducted by COO, IPAC, and UW.\r\n\r\nSome of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.\r\n\r\nThis work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.\r\n\r\nThis publication also makes use of data products from NEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of Technology, funded by the Planetary Science Division of the National Aeronautics and Space Administration.\r\n\r\nThis work is based in part on observations made with the Spitzer Space Telescope, which was operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.\r\n\r\nThe Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation.\r\n\r\nThis research relied upon the SIMBAD and VizieR databases operated by CDS (Strasbourg, France) and the bibliographic resources of The SAO Astrophysics Data System.\r\n\r\nFacilities: PO:1.2m - Palomar Observatory's 1.2 meter Samuel Oschin Telescope (Zwicky Transient Facility) - , Hale (CHIMERA, DBSP), Struve - McDonald Observatory's 2.1m Otto Struve Telescope(ProEM), Perkins - Lowell Observatory's 72in Perkins Telescope (PRISM), LDT - (LMI), Keck:I - KECK I Telescope (LRIS), Gaia - , PS1 - Panoramic Survey Telescope and Rapid Response System Telescope #1 (Pan-STARRS), Spitzer (IRAC) - , WISE - Wide-field Infrared Survey Explorer.\r\n\r\nSoftware: Astropy (Astropy Collaboration et al. 2013, 2018, 2022), astroquery (A. Ginsburg et al. 2019), ccdproc (M. Craig et al. 2017), cuvarbase (J. Hoffman 2022), extinction (K. Barbary 2016), hipercam (V. S. Dhillon et al. 2021), lmfit (M. Newville et al. 2014), matplotlib (J. D. Hunter 2007), numpy (C. R. Harris et al. 2020), pandas (The pandas Development Team 2025), phot2lc (Z. Vanderbosch 2023), photutils (L. Bradley et al. 2024), Pyriod (K. Bell 2022), scipy (P. Virtanen et al. 2020).","oa":1,"type":"journal_article","department":[{"_id":"IlCa"}],"citation":{"short":"J.A. Guidry, Z.P. Vanderbosch, J.J. Hermes, D. Veras, M.A. Hollands, S. Bhattacharjee, I. Caiazzo, K. El-Badry, M.L. Kao, L.B. Ould Rouis, A.C. Rodriguez, J. Van Roestel, The Astrophysical Journal 992 (2025).","ama":"Guidry JA, Vanderbosch ZP, Hermes JJ, et al. Transiting planetary debris near the Roche limit of a white dwarf on a 4.97 hr orbit—and its vanishing. <i>The Astrophysical Journal</i>. 2025;992(2). doi:<a href=\"https://doi.org/10.3847/1538-4357/adfecb\">10.3847/1538-4357/adfecb</a>","mla":"Guidry, Joseph A., et al. “Transiting Planetary Debris near the Roche Limit of a White Dwarf on a 4.97 Hr Orbit—and Its Vanishing.” <i>The Astrophysical Journal</i>, vol. 992, no. 2, 167, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.3847/1538-4357/adfecb\">10.3847/1538-4357/adfecb</a>.","ista":"Guidry JA, Vanderbosch ZP, Hermes JJ, Veras D, Hollands MA, Bhattacharjee S, Caiazzo I, El-Badry K, Kao ML, Ould Rouis LB, Rodriguez AC, Van Roestel J. 2025. Transiting planetary debris near the Roche limit of a white dwarf on a 4.97 hr orbit—and its vanishing. The Astrophysical Journal. 992(2), 167.","apa":"Guidry, J. A., Vanderbosch, Z. P., Hermes, J. J., Veras, D., Hollands, M. A., Bhattacharjee, S., … Van Roestel, J. (2025). Transiting planetary debris near the Roche limit of a white dwarf on a 4.97 hr orbit—and its vanishing. <i>The Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/adfecb\">https://doi.org/10.3847/1538-4357/adfecb</a>","ieee":"J. A. Guidry <i>et al.</i>, “Transiting planetary debris near the Roche limit of a white dwarf on a 4.97 hr orbit—and its vanishing,” <i>The Astrophysical Journal</i>, vol. 992, no. 2. IOP Publishing, 2025.","chicago":"Guidry, Joseph A., Zachary P. Vanderbosch, J. J. Hermes, Dimitri Veras, Mark A. Hollands, Soumyadeep Bhattacharjee, Ilaria Caiazzo, et al. “Transiting Planetary Debris near the Roche Limit of a White Dwarf on a 4.97 Hr Orbit—and Its Vanishing.” <i>The Astrophysical Journal</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.3847/1538-4357/adfecb\">https://doi.org/10.3847/1538-4357/adfecb</a>."},"article_type":"original","date_created":"2025-11-02T23:01:33Z","ddc":["520"],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"167","PlanS_conform":"1","volume":992,"has_accepted_license":"1","OA_type":"gold","quality_controlled":"1","title":"Transiting planetary debris near the Roche limit of a white dwarf on a 4.97 hr orbit—and its vanishing","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"DOAJ_listed":"1","intvolume":"       992","status":"public","language":[{"iso":"eng"}],"author":[{"full_name":"Guidry, Joseph A.","first_name":"Joseph A.","last_name":"Guidry"},{"full_name":"Vanderbosch, Zachary P.","first_name":"Zachary P.","last_name":"Vanderbosch"},{"first_name":"J. J.","full_name":"Hermes, J. J.","last_name":"Hermes"},{"full_name":"Veras, Dimitri","first_name":"Dimitri","last_name":"Veras"},{"first_name":"Mark A.","full_name":"Hollands, Mark A.","last_name":"Hollands"},{"last_name":"Bhattacharjee","full_name":"Bhattacharjee, Soumyadeep","first_name":"Soumyadeep"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","full_name":"Caiazzo, Ilaria","first_name":"Ilaria","orcid":"0000-0002-4770-5388","last_name":"Caiazzo"},{"last_name":"El-Badry","full_name":"El-Badry, Kareem","first_name":"Kareem"},{"full_name":"Kao, Malia L.","first_name":"Malia L.","last_name":"Kao"},{"full_name":"Ould Rouis, Lou Baya","first_name":"Lou Baya","last_name":"Ould Rouis"},{"first_name":"Antonio C.","full_name":"Rodriguez, Antonio C.","last_name":"Rodriguez"},{"last_name":"Van Roestel","first_name":"Jan","full_name":"Van Roestel, Jan"}],"external_id":{"arxiv":["2508.18348"],"isi":["001592080300001"]}},{"OA_type":"hybrid","has_accepted_license":"1","volume":137,"PlanS_conform":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"104206","ddc":["520"],"date_created":"2025-11-02T23:01:34Z","article_type":"original","external_id":{"arxiv":["2502.18651"],"isi":["001595690000001"]},"author":[{"first_name":"Soumyadeep","full_name":"Bhattacharjee, Soumyadeep","last_name":"Bhattacharjee"},{"last_name":"Reindl","first_name":"Nicole","full_name":"Reindl, Nicole"},{"first_name":"Howard E.","full_name":"Bond, Howard E.","last_name":"Bond"},{"last_name":"Werner","full_name":"Werner, Klaus","first_name":"Klaus"},{"full_name":"Zeimann, Gregory R.","first_name":"Gregory R.","last_name":"Zeimann"},{"last_name":"Jones","first_name":"David","full_name":"Jones, David"},{"first_name":"Kareem","full_name":"El-Badry, Kareem","last_name":"El-Badry"},{"first_name":"Nina","full_name":"Mackensen, Nina","last_name":"Mackensen"},{"first_name":"Nicholas","full_name":"Chornay, Nicholas","last_name":"Chornay"},{"first_name":"S. R.","full_name":"Kulkarni, S. R.","last_name":"Kulkarni"},{"full_name":"Caiazzo, Ilaria","first_name":"Ilaria","last_name":"Caiazzo","orcid":"0000-0002-4770-5388","id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d"},{"last_name":"Van Roestel","full_name":"Van Roestel, Jan","first_name":"Jan"},{"first_name":"Antonio C.","full_name":"Rodriguez, Antonio C.","last_name":"Rodriguez"},{"first_name":"Thomas A.","full_name":"Prince, Thomas A.","last_name":"Prince"},{"full_name":"Rusholme, Ben","first_name":"Ben","last_name":"Rusholme"},{"last_name":"Laher","first_name":"Russ R.","full_name":"Laher, Russ R."},{"first_name":"Roger","full_name":"Smith, Roger","last_name":"Smith"}],"language":[{"iso":"eng"}],"status":"public","intvolume":"       137","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"title":"Variability of central stars of planetary nebulae with the Zwicky Transient Facility. II. Long-timescale variables including wide binary and late thermal pulse candidates","quality_controlled":"1","publisher":"IOP Publishing","date_published":"2025-10-01T00:00:00Z","isi":1,"month":"10","date_updated":"2025-12-01T15:13:50Z","arxiv":1,"year":"2025","scopus_import":"1","abstract":[{"text":"In this second paper on our variability survey of central stars of planetary nebulae (CSPNe) using the Zwicky Transient Facility (ZTF), we report 11 long-timescale variables with variability timescales ranging from months to years. We also present preliminary analyses based on spectroscopic and/or photometric follow-up observations for six of them. Among them is NGC 6833, which shows a 980 days periodic variability with strange characteristics: “triangle-shaped” brightening in r, i, and WISE bands but almost coincidental shallow dips in the g-band. The most plausible explanation is a wide binary with the photometric period being the orbital period. Long-period near-sinusoidal variability was detected in two other systems, NGC 6905 and Kn 26, with periods of 700 days and 230 days, respectively, making them additional wide-binary candidates. The latter also shows a short period at 1.18 hr. We then present CTSS 2 and K 3-5, which show brightening and significant reddening over the whole ZTF baseline. A stellar model fit to the optical spectrum of CTSS 2 reveals it to be one of the youngest post-AGB CSPNe known. Both show high-density emission-line cores. We propose these to be late-thermal-pulse candidates, currently evolving towards the AGB phase. We then present recent HST/COS ultraviolet spectroscopy of the known wide-binary candidate LoTr 1, showing that the hot star is a spectroscopic twin of the extremely hot white dwarf in UCAC2 46706450. Similar to this object, LoTr 1 also has a fast rotating wide subgiant companion. We suggest that the long photometric period of 11 yr is the binary orbital period. Finally, we briefly discuss the ZTF light curves of the remaining variables, namely Tan 2, K 3-20, WHTZ 3, Kn J1857+3931, and IPHAS J1927+0814. With these examples, we present the effectiveness of the von Neumann statistics and Pearson Skew-based metric space in searching for long-timescale variables.","lang":"eng"}],"oa_version":"Published Version","file":[{"file_id":"20599","creator":"dernst","access_level":"open_access","relation":"main_file","date_created":"2025-11-04T08:26:39Z","content_type":"application/pdf","checksum":"cc7d00c349d48458accb0d3df67e4879","file_name":"2025_PASP_BhattacharjeeS.pdf","file_size":12677603,"date_updated":"2025-11-04T08:26:39Z","success":1}],"article_processing_charge":"Yes (in subscription journal)","OA_place":"publisher","publication_status":"published","type":"journal_article","department":[{"_id":"IlCa"}],"citation":{"chicago":"Bhattacharjee, Soumyadeep, Nicole Reindl, Howard E. Bond, Klaus Werner, Gregory R. Zeimann, David Jones, Kareem El-Badry, et al. “Variability of Central Stars of Planetary Nebulae with the Zwicky Transient Facility. II. Long-Timescale Variables Including Wide Binary and Late Thermal Pulse Candidates.” <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.1088/1538-3873/ae051e\">https://doi.org/10.1088/1538-3873/ae051e</a>.","ieee":"S. Bhattacharjee <i>et al.</i>, “Variability of central stars of planetary nebulae with the Zwicky Transient Facility. II. Long-timescale variables including wide binary and late thermal pulse candidates,” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 10. IOP Publishing, 2025.","ista":"Bhattacharjee S, Reindl N, Bond HE, Werner K, Zeimann GR, Jones D, El-Badry K, Mackensen N, Chornay N, Kulkarni SR, Caiazzo I, Van Roestel J, Rodriguez AC, Prince TA, Rusholme B, Laher RR, Smith R. 2025. Variability of central stars of planetary nebulae with the Zwicky Transient Facility. II. Long-timescale variables including wide binary and late thermal pulse candidates. Publications of the Astronomical Society of the Pacific. 137(10), 104206.","apa":"Bhattacharjee, S., Reindl, N., Bond, H. E., Werner, K., Zeimann, G. R., Jones, D., … Smith, R. (2025). Variability of central stars of planetary nebulae with the Zwicky Transient Facility. II. Long-timescale variables including wide binary and late thermal pulse candidates. <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing. <a href=\"https://doi.org/10.1088/1538-3873/ae051e\">https://doi.org/10.1088/1538-3873/ae051e</a>","short":"S. Bhattacharjee, N. Reindl, H.E. Bond, K. Werner, G.R. Zeimann, D. Jones, K. El-Badry, N. Mackensen, N. Chornay, S.R. Kulkarni, I. Caiazzo, J. Van Roestel, A.C. Rodriguez, T.A. Prince, B. Rusholme, R.R. Laher, R. Smith, Publications of the Astronomical Society of the Pacific 137 (2025).","mla":"Bhattacharjee, Soumyadeep, et al. “Variability of Central Stars of Planetary Nebulae with the Zwicky Transient Facility. II. Long-Timescale Variables Including Wide Binary and Late Thermal Pulse Candidates.” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 10, 104206, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.1088/1538-3873/ae051e\">10.1088/1538-3873/ae051e</a>.","ama":"Bhattacharjee S, Reindl N, Bond HE, et al. Variability of central stars of planetary nebulae with the Zwicky Transient Facility. II. Long-timescale variables including wide binary and late thermal pulse candidates. <i>Publications of the Astronomical Society of the Pacific</i>. 2025;137(10). doi:<a href=\"https://doi.org/10.1088/1538-3873/ae051e\">10.1088/1538-3873/ae051e</a>"},"oa":1,"publication_identifier":{"issn":["1538-3873"]},"acknowledgement":"This work is based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under grant Nos. AST-1440341 and AST-2034437 and a collaboration including current partners Caltech, IPAC, the Oskar Klein Center at Stockholm University, the University of Maryland, University of California, Berkeley, the University of Wisconsin at Milwaukee, University of Warwick, Ruhr University Bochum, Cornell University, Northwestern University, and Drexel University. Operations are conducted by COO, IPAC, and UW.\r\n\r\nThis work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular, the institutions participating in the Gaia Multilateral Agreement.\r\n\r\nWe are grateful to the staffs of Palomar Observatory and the Hobby-Eberly Telescope for assistance with the observations and data management. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council.\r\n\r\nThe Low-Resolution Spectrograph 2 (LRS2) on HET was developed and funded by the University of Texas at Austin McDonald Observatory and Department of Astronomy, and by Pennsylvania State University. We thank the Leibniz-Institut für Astrophysik Potsdam (AIP) and the Institut für Astrophysik Göttingen (IAG) for their contributions to the construction of the integral field units. We acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing high performance computing, visualization, and storage resources that have contributed to the results reported within this paper.\r\n\r\nThe Isaac Newton Telescope is operated on the island of La Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias\r\n\r\nS.B. thanks Frank J. Masci and Zachary P. Vanderbosch for useful discussions and suggestions regarding solving the issues with ZTF forced photometry on extended sources. S.B. also thanks Jim Fuller, Charles C. Steidel, Lynne Hillenbrand, and Adolfo Carvalho for useful discussions on methods and science. S.B. acknowledges financial support from the Wallace L. W. Sargent Graduate Fellowship during the first year of his graduate studies at Caltech. N.C. was supported through the Cancer Research UK grant A24042.\r\n\r\nN.R. is supported by the Deutsche Forschungsgemeinschaft (DFG) through grant RE3915/2-1.\r\n\r\nD.J. acknowledges support from the Agencia Estatal de Investigación del Ministerio de Ciencia, Innovación y Universidades (MICIU/AEI) under grant “Nebulosas planetarias como clave para comprender la evolución de estrellas binarias” and the European Regional Development Fund (ERDF) with reference PID-2022-136653NA-I00 (DOI:10.13039/501100011033). D.J. also acknowledges support from the Agencia Estatal de Investigación del Ministerio de Ciencia, Innovación y Universidades (MICIU/AEI) under grant “Revolucionando el conocimiento de la evolución de estrellas poco masivas” and the the European Union NextGenerationEU/PRTR with reference CNS2023-143910 (DOI:10.13039/501100011033).\r\n\r\nWe have used Python packages Numpy (Harris et al. 2020), SciPy (Virtanen et al. 2020), Matplotlib (Hunter 2007), Pandas (pandas development team 2020), Astropy (Astropy Collaboration et al. 2013, 2018), and Astroquery (Ginsburg et al. 2019) at various stages of this research.","doi":"10.1088/1538-3873/ae051e","_id":"20588","day":"01","publication":"Publications of the Astronomical Society of the Pacific","issue":"10","file_date_updated":"2025-11-04T08:26:39Z"},{"volume":137,"has_accepted_license":"1","OA_type":"hybrid","article_type":"original","ddc":["520"],"date_created":"2025-01-19T23:01:51Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"014201","intvolume":"       137","status":"public","external_id":{"arxiv":["2408.16053"],"isi":["001393204700001"]},"author":[{"last_name":"Rodriguez","first_name":"Antonio C.","full_name":"Rodriguez, Antonio C."},{"last_name":"El-Badry","first_name":"Kareem","full_name":"El-Badry, Kareem"},{"last_name":"Suleimanov","full_name":"Suleimanov, Valery","first_name":"Valery"},{"first_name":"Anna F.","full_name":"Pala, Anna F.","last_name":"Pala"},{"last_name":"Kulkarni","full_name":"Kulkarni, Shrinivas R.","first_name":"Shrinivas R."},{"first_name":"Boris","full_name":"Gaensicke, Boris","last_name":"Gaensicke"},{"full_name":"Mori, Kaya","first_name":"Kaya","last_name":"Mori"},{"last_name":"Rich","first_name":"R. Michael","full_name":"Rich, R. Michael"},{"full_name":"Sarkar, Arnab","first_name":"Arnab","last_name":"Sarkar"},{"full_name":"Bao, Tong","first_name":"Tong","last_name":"Bao"},{"last_name":"De Oliveira","full_name":"De Oliveira, Raimundo Lopes","first_name":"Raimundo Lopes"},{"last_name":"Ramsay","full_name":"Ramsay, Gavin","first_name":"Gavin"},{"last_name":"Szkody","full_name":"Szkody, Paula","first_name":"Paula"},{"last_name":"Graham","full_name":"Graham, Matthew","first_name":"Matthew"},{"last_name":"Prince","full_name":"Prince, Thomas A.","first_name":"Thomas A."},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","last_name":"Caiazzo","orcid":"0000-0002-4770-5388","full_name":"Caiazzo, Ilaria","first_name":"Ilaria"},{"full_name":"Vanderbosch, Zachary P.","first_name":"Zachary P.","last_name":"Vanderbosch"},{"full_name":"Roestel, Jan Van","first_name":"Jan Van","last_name":"Roestel"},{"full_name":"Das, Kaustav K.","first_name":"Kaustav K.","last_name":"Das"},{"full_name":"Qin, Yu Jing","first_name":"Yu Jing","last_name":"Qin"},{"first_name":"Mansi M.","full_name":"Kasliwal, Mansi M.","last_name":"Kasliwal"},{"first_name":"Avery","full_name":"Wold, Avery","last_name":"Wold"},{"first_name":"Steven L.","full_name":"Groom, Steven L.","last_name":"Groom"},{"last_name":"Reiley","first_name":"Daniel","full_name":"Reiley, Daniel"},{"full_name":"Riddle, Reed","first_name":"Reed","last_name":"Riddle"}],"language":[{"iso":"eng"}],"license":"https://creativecommons.org/licenses/by/3.0/","title":"Cataclysmic variables and AM CVn binaries in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions, and space densities","quality_controlled":"1","tmp":{"name":"Creative Commons Attribution 3.0 Unported (CC BY 3.0)","short":"CC BY (3.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/3.0/legalcode"},"scopus_import":"1","year":"2025","abstract":[{"text":"We present volume-limited samples of cataclysmic variables (CVs) and AM CVn binaries jointly selected from SRG/eROSITA eRASS1 and Gaia DR3 using an X-ray + optical color–color diagram (the \"X-ray Main Sequence\"). This tool identifies all CV subtypes, including magnetic and low-accretion rate systems, in contrast to most previous surveys. We find 23 CVs, 3 of which are AM CVns, out to 150 pc in the Western Galactic Hemisphere. Our 150 pc sample is spectroscopically verified and complete down to LX = 1.3 × 1029 erg s−1 in the 0.2–2.3 keV band, and we also present CV candidates out to 300 pc and 1000 pc. We discovered two previously unknown systems in our 150 pc sample: the third nearest AM CVn and a magnetic period bouncer. We find the mean LX of CVs to be 〈LX〉 ≈ 4.6 × 1030 erg s−1, in contrast to previous surveys which yielded 〈LX〉 ∼ 1031−1032 erg s−1. We construct X-ray luminosity functions that, for the first time, flatten out at LX ∼ 1030 erg s−1. We infer average number, mass, and luminosity densities of ρN,CV = (3.7 ± 0.7) × 10−6pc−3, (math formular), and (math formular), respectively, in the solar neighborhood. Our uniform selection method also allows us to place meaningful estimates on the space density of AM CVns, ρN,AM CVn = (5.5 ± 3.7) × 10−7 pc−3. Magnetic CVs and period bouncers make up 35% and 25% of our sample, respectively. This work, through a novel discovery technique, shows that the observed number densities of CVs and AM CVns, as well as the fraction of period bouncers, are still in tension with population synthesis estimates.","lang":"eng"}],"isi":1,"month":"01","arxiv":1,"date_updated":"2025-02-27T12:46:32Z","publisher":"IOP Publishing","date_published":"2025-01-01T00:00:00Z","OA_place":"publisher","publication_status":"published","article_processing_charge":"No","file":[{"file_id":"18860","access_level":"open_access","creator":"dernst","date_created":"2025-01-20T09:52:34Z","relation":"main_file","content_type":"application/pdf","file_name":"2025_PASP_Rodriguez.pdf","checksum":"02a9be04a6704fc272ed5a976e5fa8c5","file_size":5155631,"success":1,"date_updated":"2025-01-20T09:52:34Z"}],"oa_version":"Published Version","acknowledgement":"We thank Roman Krivonos for insightful feedback, Kevin Burdge, Dovi Poznanski, and Jim Fuller for useful discussions, and Sunny Wong for providing AM CVn evolutionary models. A.C.R. acknowledges support from an NSF Graduate Fellowship.\r\n\r\nA.C.R. thanks the LSST-DA Data Science Fellowship Program, which is funded by LSST-DA, the Brinson Foundation, and the Moore Foundation; his participation in the program has benefited this work. RLO is a Research Fellow of the Brazilian institution CNPq (PQ-315632/2023-2).\r\n\r\nThis work is based on data from eROSITA, the soft X-ray instrument aboard SRG, a joint Russian-German science mission supported by the Russian Space Agency (Roskosmos), in the interests of the Russian Academy of Sciences represented by its Space Research Institute (IKI), and the Deutsches Zentrum für Luft- und Raumfahrt (DLR). The SRG spacecraft was built by Lavochkin Association (NPOL) and its subcontractors, and is operated by NPOL with support from the Max Planck Institute for Extraterrestrial Physics (MPE). The development and construction of the eROSITA X-ray instrument was led by MPE, with contributions from the Dr. Karl Remeis Observatory Bamberg & ECAP (FAU Erlangen-Nuernberg), the University of Hamburg Observatory, the Leibniz Institute for Astrophysics Potsdam (AIP), and the Institute for Astronomy and Astrophysics of the University of Tübingen, with the support of DLR and the Max Planck Society. The Argelander Institute for Astronomy of the University of Bonn and the Ludwig Maximilians Universität Munich also participated in the science preparation for eROSITA.\r\n\r\nThis work presents results from the European Space Agency (ESA) space mission Gaia. Gaia data are being processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC is provided by national institutions, in particular the institutions participating in the Gaia MultiLateral Agreement (MLA). The Gaia mission website is https://www.cosmos.esa.int/gaia. The Gaia archive website is https://archives.esac.esa.int/gaia.\r\n\r\nSome of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. We are also grateful to the staff of Palomar Observatory and that of Lick Observatory for their assistance in carrying out observations used in this work.\r\n\r\nBased on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under grants No. AST-1440341 and AST-2034437 and a collaboration including current partners Caltech, IPAC, the Weizmann Institute of Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, IN2P3, University of Warwick, Ruhr University Bochum, Northwestern University and former partners the University of Washington, Los Alamos National Laboratories, and Lawrence Berkeley National Laboratories. Operations are conducted by COO, IPAC, and UW.\r\n\r\nSoftware: used: Python and the following libraries: matplotlib (Hunter 2007), scipy (Virtanen et al. 2020), astropy (Astropy Collaboration et al. 2013), numpy (van der Walt et al. 2011). PypeIt (Prochaska et al. 2020), lpipe (Perley 2019), and Tool for OPerations on Catalogues And Tables (TOPCAT) (Taylor 2005).","publication_identifier":{"issn":["0004-6280"]},"doi":"10.1088/1538-3873/ada185","oa":1,"citation":{"chicago":"Rodriguez, Antonio C., Kareem El-Badry, Valery Suleimanov, Anna F. Pala, Shrinivas R. Kulkarni, Boris Gaensicke, Kaya Mori, et al. “Cataclysmic Variables and AM CVn Binaries in SRG/EROSITA + Gaia: Volume Limited Samples, X-Ray Luminosity Functions, and Space Densities.” <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.1088/1538-3873/ada185\">https://doi.org/10.1088/1538-3873/ada185</a>.","ieee":"A. C. Rodriguez <i>et al.</i>, “Cataclysmic variables and AM CVn binaries in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions, and space densities,” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 1. IOP Publishing, 2025.","apa":"Rodriguez, A. C., El-Badry, K., Suleimanov, V., Pala, A. F., Kulkarni, S. R., Gaensicke, B., … Riddle, R. (2025). Cataclysmic variables and AM CVn binaries in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions, and space densities. <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing. <a href=\"https://doi.org/10.1088/1538-3873/ada185\">https://doi.org/10.1088/1538-3873/ada185</a>","ista":"Rodriguez AC, El-Badry K, Suleimanov V, Pala AF, Kulkarni SR, Gaensicke B, Mori K, Rich RM, Sarkar A, Bao T, De Oliveira RL, Ramsay G, Szkody P, Graham M, Prince TA, Caiazzo I, Vanderbosch ZP, Roestel JV, Das KK, Qin YJ, Kasliwal MM, Wold A, Groom SL, Reiley D, Riddle R. 2025. Cataclysmic variables and AM CVn binaries in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions, and space densities. Publications of the Astronomical Society of the Pacific. 137(1), 014201.","ama":"Rodriguez AC, El-Badry K, Suleimanov V, et al. Cataclysmic variables and AM CVn binaries in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions, and space densities. <i>Publications of the Astronomical Society of the Pacific</i>. 2025;137(1). doi:<a href=\"https://doi.org/10.1088/1538-3873/ada185\">10.1088/1538-3873/ada185</a>","mla":"Rodriguez, Antonio C., et al. “Cataclysmic Variables and AM CVn Binaries in SRG/EROSITA + Gaia: Volume Limited Samples, X-Ray Luminosity Functions, and Space Densities.” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 1, 014201, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.1088/1538-3873/ada185\">10.1088/1538-3873/ada185</a>.","short":"A.C. Rodriguez, K. El-Badry, V. Suleimanov, A.F. Pala, S.R. Kulkarni, B. Gaensicke, K. Mori, R.M. Rich, A. Sarkar, T. Bao, R.L. De Oliveira, G. Ramsay, P. Szkody, M. Graham, T.A. Prince, I. Caiazzo, Z.P. Vanderbosch, J.V. Roestel, K.K. Das, Y.J. Qin, M.M. Kasliwal, A. Wold, S.L. Groom, D. Reiley, R. Riddle, Publications of the Astronomical Society of the Pacific 137 (2025)."},"department":[{"_id":"IlCa"}],"type":"journal_article","issue":"1","file_date_updated":"2025-01-20T09:52:34Z","publication":"Publications of the Astronomical Society of the Pacific","_id":"18851","day":"01"},{"publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"acknowledgement":"This project was originally started as part of the Kavli Summer Program which took place in the Max Planck Institute for Astrophysics in Garching in July 2023, supported by the Kavli Foundation. We are grateful to Stephen Justham, Selma de Mink, and Jim Fuller for enriching discussions. We would like to thank the anonymous referee for their helpful report. A.B. was supported by the Deutsche Forschungsgemeinschaft (DFG) through grant GE2506/18-1. K.J.S. was supported by NASA through the Astrophysics Theory Program (80NSSC20K0544) and by NASA/ESA Hubble Space Telescope programs #15871 and #15918. W.E.K. was supported by NSF Grants OAC-2311323, AST-2206523, and NASA/ESA HST-AR-Theory HSTAR-16613.002-A. K.E. was supported in part by HST-GO-17441.001-A. AB and ASR would like to thank Rob Farmer for his support with PyMESA.","doi":"10.1051/0004-6361/202451371","oa":1,"department":[{"_id":"IlCa"}],"type":"journal_article","citation":{"apa":"Bhat, A., Bauer, E. B., Pakmor, R., Shen, K. J., Caiazzo, I., Rajamuthukumar, A. S., … Kerzendorf, W. E. (2025). Supernova shocks cannot explain the inflated state of hypervelocity runaways from white dwarf binaries. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202451371\">https://doi.org/10.1051/0004-6361/202451371</a>","ista":"Bhat A, Bauer EB, Pakmor R, Shen KJ, Caiazzo I, Rajamuthukumar AS, El-Badry K, Kerzendorf WE. 2025. Supernova shocks cannot explain the inflated state of hypervelocity runaways from white dwarf binaries. Astronomy &#38; Astrophysics. 693(1), A114.","short":"A. Bhat, E.B. Bauer, R. Pakmor, K.J. Shen, I. Caiazzo, A.S. Rajamuthukumar, K. El-Badry, W.E. Kerzendorf, Astronomy &#38; Astrophysics 693 (2025).","ama":"Bhat A, Bauer EB, Pakmor R, et al. Supernova shocks cannot explain the inflated state of hypervelocity runaways from white dwarf binaries. <i>Astronomy &#38; Astrophysics</i>. 2025;693(1). doi:<a href=\"https://doi.org/10.1051/0004-6361/202451371\">10.1051/0004-6361/202451371</a>","mla":"Bhat, Aakash, et al. “Supernova Shocks Cannot Explain the Inflated State of Hypervelocity Runaways from White Dwarf Binaries.” <i>Astronomy &#38; Astrophysics</i>, vol. 693, no. 1, A114, EDP Sciences, 2025, doi:<a href=\"https://doi.org/10.1051/0004-6361/202451371\">10.1051/0004-6361/202451371</a>.","chicago":"Bhat, Aakash, Evan B. Bauer, Rüdiger Pakmor, Ken J. Shen, Ilaria Caiazzo, Abinaya Swaruba Rajamuthukumar, Kareem El-Badry, and Wolfgang E. Kerzendorf. “Supernova Shocks Cannot Explain the Inflated State of Hypervelocity Runaways from White Dwarf Binaries.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2025. <a href=\"https://doi.org/10.1051/0004-6361/202451371\">https://doi.org/10.1051/0004-6361/202451371</a>.","ieee":"A. Bhat <i>et al.</i>, “Supernova shocks cannot explain the inflated state of hypervelocity runaways from white dwarf binaries,” <i>Astronomy &#38; Astrophysics</i>, vol. 693, no. 1. EDP Sciences, 2025."},"issue":"1","file_date_updated":"2025-01-20T09:57:00Z","publication":"Astronomy & Astrophysics","day":"07","_id":"18852","abstract":[{"lang":"eng","text":"Recent observations have found a growing number of hypervelocity stars with speeds of ≈1500 − 2500 km s−1 that could have only been produced through thermonuclear supernovae in white dwarf binaries. Most of the observed hypervelocity runaways in this class display a surprising inflated structure: their current radii are roughly an order of magnitude greater than they would have been as white dwarfs filling their Roche lobe. While many simulations exist studying the dynamical phase leading to supernova detonation in these systems, no detailed calculations of the long-term structure of the runaways have yet been performed. We used an existing AREPO hydrodynamical simulation of a supernova in a white dwarf binary as a starting point for the evolution of these stars with the one-dimensional stellar evolution code MESA. We show that the supernova shock is not energetic enough to inflate the white dwarf over timescales longer than a few thousand years, significantly shorter than the 105 − 6 year lifetimes inferred for observed hypervelocity runaways. Although they experience a shock from a supernova less than ≈0.02 R⊙ away, our models do not experience significant interior heating, and all contract back to radii of around 0.01 R⊙ within about 104 years. Explaining the observed inflated states requires either an additional source of significant heating or some other physics that is not yet accounted for in the subsequent evolution."}],"year":"2025","scopus_import":"1","month":"01","isi":1,"date_updated":"2026-02-16T12:08:05Z","arxiv":1,"publisher":"EDP Sciences","date_published":"2025-01-07T00:00:00Z","OA_place":"publisher","publication_status":"published","article_processing_charge":"No","file":[{"file_id":"18861","access_level":"open_access","creator":"dernst","date_created":"2025-01-20T09:57:00Z","relation":"main_file","content_type":"application/pdf","file_name":"2025_AstronomyAstrophysics_Bhat.pdf","checksum":"e532b9c8123c29cfb0ee758e6d00453c","file_size":1692527,"date_updated":"2025-01-20T09:57:00Z","success":1}],"oa_version":"Published Version","intvolume":"       693","status":"public","external_id":{"isi":["001406577300001"],"arxiv":["2407.03424"]},"author":[{"last_name":"Bhat","full_name":"Bhat, Aakash","first_name":"Aakash"},{"last_name":"Bauer","full_name":"Bauer, Evan B.","first_name":"Evan B."},{"last_name":"Pakmor","full_name":"Pakmor, Rüdiger","first_name":"Rüdiger"},{"last_name":"Shen","full_name":"Shen, Ken J.","first_name":"Ken J."},{"first_name":"Ilaria","full_name":"Caiazzo, Ilaria","last_name":"Caiazzo","orcid":"0000-0002-4770-5388","id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d"},{"last_name":"Rajamuthukumar","full_name":"Rajamuthukumar, Abinaya Swaruba","first_name":"Abinaya Swaruba"},{"last_name":"El-Badry","first_name":"Kareem","full_name":"El-Badry, Kareem"},{"last_name":"Kerzendorf","full_name":"Kerzendorf, Wolfgang E.","first_name":"Wolfgang E."}],"language":[{"iso":"eng"}],"title":"Supernova shocks cannot explain the inflated state of hypervelocity runaways from white dwarf binaries","quality_controlled":"1","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"volume":693,"has_accepted_license":"1","OA_type":"diamond","article_type":"original","ddc":["520"],"date_created":"2025-01-19T23:01:51Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"A114"},{"quality_controlled":"1","title":"JWST photometry and astrometry of 47 Tucanae. Discontinuity in the stellar sequence at the star--brown dwarf transition","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"status":"public","intvolume":"       694","language":[{"iso":"eng"}],"author":[{"first_name":"M.","full_name":"Scalco, M.","last_name":"Scalco"},{"last_name":"Gerasimov","first_name":"R.","full_name":"Gerasimov, R."},{"last_name":"Bedin","first_name":"L. R.","full_name":"Bedin, L. R."},{"last_name":"Vesperini","first_name":"E.","full_name":"Vesperini, E."},{"full_name":"Correnti, M.","first_name":"M.","last_name":"Correnti"},{"full_name":"Nardiello, D.","first_name":"D.","last_name":"Nardiello"},{"first_name":"A.","full_name":"Burgasser, A.","last_name":"Burgasser"},{"full_name":"Richer, H.","first_name":"H.","last_name":"Richer"},{"last_name":"Caiazzo","orcid":"0000-0002-4770-5388","first_name":"Ilaria","full_name":"Caiazzo, Ilaria","id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d"},{"full_name":"Heyl, J.","first_name":"J.","last_name":"Heyl"},{"full_name":"Libralato, M.","first_name":"M.","last_name":"Libralato"},{"last_name":"Anderson","full_name":"Anderson, J.","first_name":"J."},{"last_name":"Griggio","first_name":"M.","full_name":"Griggio, M."}],"external_id":{"arxiv":["2501.04446"],"isi":["001414753300007"]},"date_created":"2025-01-21T15:29:36Z","ddc":["520"],"article_type":"original","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_number":"A68","volume":694,"OA_type":"diamond","has_accepted_license":"1","publication":"Astronomy & Astrophysics","file_date_updated":"2025-04-16T07:13:31Z","_id":"18866","day":"04","doi":"10.1051/0004-6361/202452907","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"acknowledgement":"We dedicate this paper to the memory of our colleague Prof. Harvey Richer (⋆ April 1944 —† 13 November 2023), a highly accomplished astronomer and expert in stellar populations and in particular within globular clusters, who passed away during this project. Harvey grew up in Montreal and was at least the second star man to graduate from his high school, having been preceded by William Shatner by more than a decade. He worked at the University of British Columbia for most of his career, and his focus was the late stages of stellar evolution, in particular carbon stars and white dwarfs. We thank the referee for his valuable suggestions and comments, which helped improve the paper, as well as for his prompt revision.","department":[{"_id":"IlCa"}],"citation":{"apa":"Scalco, M., Gerasimov, R., Bedin, L. R., Vesperini, E., Correnti, M., Nardiello, D., … Griggio, M. (2025). JWST photometry and astrometry of 47 Tucanae. Discontinuity in the stellar sequence at the star--brown dwarf transition. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202452907\">https://doi.org/10.1051/0004-6361/202452907</a>","ista":"Scalco M, Gerasimov R, Bedin LR, Vesperini E, Correnti M, Nardiello D, Burgasser A, Richer H, Caiazzo I, Heyl J, Libralato M, Anderson J, Griggio M. 2025. JWST photometry and astrometry of 47 Tucanae. Discontinuity in the stellar sequence at the star--brown dwarf transition. Astronomy &#38; Astrophysics. 694, A68.","short":"M. Scalco, R. Gerasimov, L.R. Bedin, E. Vesperini, M. Correnti, D. Nardiello, A. Burgasser, H. Richer, I. Caiazzo, J. Heyl, M. Libralato, J. Anderson, M. Griggio, Astronomy &#38; Astrophysics 694 (2025).","mla":"Scalco, M., et al. “JWST Photometry and Astrometry of 47 Tucanae. Discontinuity in the Stellar Sequence at the Star--Brown Dwarf Transition.” <i>Astronomy &#38; Astrophysics</i>, vol. 694, A68, EDP Sciences, 2025, doi:<a href=\"https://doi.org/10.1051/0004-6361/202452907\">10.1051/0004-6361/202452907</a>.","ama":"Scalco M, Gerasimov R, Bedin LR, et al. JWST photometry and astrometry of 47 Tucanae. Discontinuity in the stellar sequence at the star--brown dwarf transition. <i>Astronomy &#38; Astrophysics</i>. 2025;694. doi:<a href=\"https://doi.org/10.1051/0004-6361/202452907\">10.1051/0004-6361/202452907</a>","chicago":"Scalco, M., R. Gerasimov, L. R. Bedin, E. Vesperini, M. Correnti, D. Nardiello, A. Burgasser, et al. “JWST Photometry and Astrometry of 47 Tucanae. Discontinuity in the Stellar Sequence at the Star--Brown Dwarf Transition.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2025. <a href=\"https://doi.org/10.1051/0004-6361/202452907\">https://doi.org/10.1051/0004-6361/202452907</a>.","ieee":"M. Scalco <i>et al.</i>, “JWST photometry and astrometry of 47 Tucanae. Discontinuity in the stellar sequence at the star--brown dwarf transition,” <i>Astronomy &#38; Astrophysics</i>, vol. 694. EDP Sciences, 2025."},"type":"journal_article","oa":1,"article_processing_charge":"Yes","OA_place":"publisher","publication_status":"published","file":[{"date_updated":"2025-04-16T07:13:31Z","success":1,"file_size":18080704,"file_name":"2025_AstronomyAstrophysics_Scalco.pdf","checksum":"db765ce222df60a1e7c19da1968906a8","content_type":"application/pdf","date_created":"2025-04-16T07:13:31Z","relation":"main_file","access_level":"open_access","creator":"dernst","file_id":"19569"}],"oa_version":"Published Version","date_updated":"2025-07-10T11:51:28Z","arxiv":1,"month":"02","isi":1,"year":"2025","abstract":[{"lang":"eng","text":"Using JWST Near Infrared Camera (NIRCam) images of the globular cluster 47,Tucanæ, (or NGC,104), taken at two epochs just 7 months apart, we derived proper-motion membership down to F322W2 ∼ 27. We identified an intriguing feature at the very low-mass end of the main sequence, around ∼ 0.08,M_⋅, at magnitudes F322W2 ∼ 24 and m_ F150W2 ∼ 25. This feature, dubbed 'kink', is characterized by a prominent discontinuity in the slope of the main sequence. A similar discontinuity is seen in theoretical isochrones with oxygen-poor chemistries, related to the rapid onset of absorption. We therefore hypothesize that the cluster hosts disproportionately more oxygen-poor stars near the bottom of the main sequence compared to the upper main sequence and the red giant branch. Our results show no strong or conclusive evidence of a rise in the brown dwarf luminosity function at faint magnitudes, in contrast to previous findings likely affected by faint red background galaxies. In our analysis, we accounted for this contamination by using proper motion membership."}],"scopus_import":"1","date_published":"2025-02-04T00:00:00Z","publisher":"EDP Sciences"},{"year":"2025","abstract":[{"text":"A complete understanding of the central stars of planetary nebulae (CSPNe) remains elusive. Over the past several decades, time-series photometry of CSPNe has yielded significant results including, but not limited to, discoveries of nearly 100 binary systems, insights into pulsations and winds in young white dwarfs, and studies of stars undergoing very late thermal pulses. We have undertaken a systematic study of optical photometric variability of cataloged CSPNe, using the light curves from the Zwicky Transient Facility (ZTF). By applying appropriate variability metrics, we arrive at a list of 94 highly variable CSPN candidates. Based on the timescales of the light-curve activity, we classify the variables broadly into short- and long-timescale variables. In this first paper in this series, we focus on the former, which is the majority class comprising 83 objects. We report periods for six sources for the first time, and recover several known periodic variables. Among the aperiodic sources, most exhibit a jitter around a median flux with a stable amplitude, and a few show outbursts. We draw attention to WeSb 1, which shows a different kind of variability: prominent deep and aperiodic dips, resembling transits from a dust/debris disk. We find strong evidence for a binary nature of WeSb 1 (possibly an F-type subgiant companion). The compactness of the emission lines and inferred high electron densities make WeSb 1 a candidate for either an EGB 6-type planetary nucleus, or a symbiotic system inside an evolved planetary nebula, both of which are rare objects. To demonstrate further promise with ZTF, we report three additional newly identified periodic sources that do not appear in the list of highly variable sources. Finally, we also introduce a two-dimensional metric space defined by the von Neumann statistics and Pearson Skew and demonstrate its effectiveness in identifying unique variables of astrophysical interest, like WeSb 1.","lang":"eng"}],"scopus_import":"1","month":"02","isi":1,"date_updated":"2025-09-30T10:32:17Z","arxiv":1,"publisher":"IOP Publishing","date_published":"2025-02-01T00:00:00Z","OA_place":"publisher","publication_status":"published","article_processing_charge":"No","oa_version":"Published Version","file":[{"relation":"main_file","date_created":"2025-02-17T09:13:41Z","creator":"dernst","access_level":"open_access","file_id":"19034","success":1,"date_updated":"2025-02-17T09:13:41Z","file_size":3657568,"checksum":"42b942ee1bf32ed225024e168174be92","file_name":"2025_PASP_Bhattacharjee.pdf","content_type":"application/pdf"}],"publication_identifier":{"issn":["0004-6280"],"issnl":["0004-6280"]},"acknowledgement":"This work is based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under grants No. AST-1440341 and AST-2034437 and a collaboration including current partners Caltech, IPAC, the Oskar Klein Center at Stockholm University, the University of Maryland, University of California, Berkeley, the University of Wisconsin at Milwaukee, University of Warwick, Ruhr University Bochum, Cornell University, Northwestern University, and Drexel University. Operations are conducted by COO, IPAC, and UW.\r\n\r\nThis work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular, the institutions participating in the Gaia Multilateral Agreement.\r\n\r\nWe are grateful to the staffs of Palomar Observatory and the Hobby-Eberly Telescope for assistance with the observations and data management. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council.\r\n\r\nThe Low-Resolution Spectrograph 2 (LRS2) on HET was developed and funded by the University of Texas at Austin McDonald Observatory and Department of Astronomy, and by Pennsylvania State University. We thank the Leibniz-Institut für Astrophysik Potsdam (AIP) and the Institut für Astrophysik Göttingen (IAG) for their contributions to the construction of the integral field units. We acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing high performance computing, visualization, and storage resources that have contributed to the results reported within this paper.\r\n\r\nWe thank the anonymous referee for the detailed comments, which improved the clarity of the manuscript significantly. We also thank Gunter Cibis for pointing out typographical errors in the names of a few PNe in the first draft. S.B. expresses gratitude to Kishalay De for providing the Gattini-IR and WISE data. S.B. thanks Frank J. Masci and Zachary P. Vanderbosch for useful discussions and suggestions regarding solving the issues with ZTF forced photometry on extended sources. S.B. also thanks Jim Fuller, Charles C. Steidel, Lynne Hillenbrand, and Adolfo Carvalho for useful discussions on methods and science. S.B. also thanks David O. Cook for providing access to his CLU image cutout service to generate the WeSb 1 image. S.B. acknowledges the financial support from the Wallace L. W. Sargent Graduate Fellowship during the first year of his graduate studies at Caltech. N.C. was supported through the Cancer Research UK grant A24042. S.B. thanks Martina Veresvarka for drawing our attention to the TESS light curves of WeSb 1.\r\n\r\nWe have used Python packages Numpy (Harris et al. 2020), SciPy (Virtanen et al. 2020), Matplotlib (Hunter 2007), Pandas (pandas development team 2020), Astropy (Astropy Collaboration et al. 2013, 2018), and Astroquery (Ginsburg et al. 2019) at various stages of this research.","doi":"10.1088/1538-3873/ada702","oa":1,"type":"journal_article","department":[{"_id":"IlCa"}],"citation":{"ama":"Bhattacharjee S, Kulkarni SR, Kong AKH, et al. Variability of central stars of planetary nebulae with the zwicky transient facility. I. Methods, short-timescale variables, and the unusual nucleus of WeSb 1. <i>Publications of the Astronomical Society of the Pacific</i>. 2025;137(2). doi:<a href=\"https://doi.org/10.1088/1538-3873/ada702\">10.1088/1538-3873/ada702</a>","mla":"Bhattacharjee, Soumyadeep, et al. “Variability of Central Stars of Planetary Nebulae with the Zwicky Transient Facility. I. Methods, Short-Timescale Variables, and the Unusual Nucleus of WeSb 1.” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 2, 024201, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.1088/1538-3873/ada702\">10.1088/1538-3873/ada702</a>.","short":"S. Bhattacharjee, S.R. Kulkarni, A.K.H. Kong, M.S. Tam, H.E. Bond, K. El-Badry, I. Caiazzo, N. Chornay, M.J. Graham, A.C. Rodriguez, G.R. Zeimann, C. Fremling, A.J. Drake, K. Werner, H. Rodriguez, T.A. Prince, R.R. Laher, T.X. Chen, R. Riddle, Publications of the Astronomical Society of the Pacific 137 (2025).","apa":"Bhattacharjee, S., Kulkarni, S. R., Kong, A. K. H., Tam, M. S., Bond, H. E., El-Badry, K., … Riddle, R. (2025). Variability of central stars of planetary nebulae with the zwicky transient facility. I. Methods, short-timescale variables, and the unusual nucleus of WeSb 1. <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing. <a href=\"https://doi.org/10.1088/1538-3873/ada702\">https://doi.org/10.1088/1538-3873/ada702</a>","ista":"Bhattacharjee S, Kulkarni SR, Kong AKH, Tam MS, Bond HE, El-Badry K, Caiazzo I, Chornay N, Graham MJ, Rodriguez AC, Zeimann GR, Fremling C, Drake AJ, Werner K, Rodriguez H, Prince TA, Laher RR, Chen TX, Riddle R. 2025. Variability of central stars of planetary nebulae with the zwicky transient facility. I. Methods, short-timescale variables, and the unusual nucleus of WeSb 1. Publications of the Astronomical Society of the Pacific. 137(2), 024201.","ieee":"S. Bhattacharjee <i>et al.</i>, “Variability of central stars of planetary nebulae with the zwicky transient facility. I. Methods, short-timescale variables, and the unusual nucleus of WeSb 1,” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 2. IOP Publishing, 2025.","chicago":"Bhattacharjee, Soumyadeep, S. R. Kulkarni, Albert K.H. Kong, M. S. Tam, Howard E. Bond, Kareem El-Badry, Ilaria Caiazzo, et al. “Variability of Central Stars of Planetary Nebulae with the Zwicky Transient Facility. I. Methods, Short-Timescale Variables, and the Unusual Nucleus of WeSb 1.” <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.1088/1538-3873/ada702\">https://doi.org/10.1088/1538-3873/ada702</a>."},"issue":"2","file_date_updated":"2025-02-17T09:13:41Z","publication":"Publications of the Astronomical Society of the Pacific","day":"01","_id":"19025","related_material":{"link":[{"url":"https://doi.org/10.1088/1538-3873/adbcd8","relation":"erratum"}]},"volume":137,"has_accepted_license":"1","article_type":"original","ddc":["520"],"date_created":"2025-02-16T23:02:33Z","article_number":"024201","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","intvolume":"       137","status":"public","external_id":{"isi":["001416903300001"],"arxiv":["2410.03589"]},"author":[{"full_name":"Bhattacharjee, Soumyadeep","first_name":"Soumyadeep","last_name":"Bhattacharjee"},{"first_name":"S. R.","full_name":"Kulkarni, S. R.","last_name":"Kulkarni"},{"first_name":"Albert K.H.","full_name":"Kong, Albert K.H.","last_name":"Kong"},{"last_name":"Tam","first_name":"M. S.","full_name":"Tam, M. S."},{"last_name":"Bond","first_name":"Howard E.","full_name":"Bond, Howard E."},{"first_name":"Kareem","full_name":"El-Badry, Kareem","last_name":"El-Badry"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","full_name":"Caiazzo, Ilaria","first_name":"Ilaria","last_name":"Caiazzo","orcid":"0000-0002-4770-5388"},{"last_name":"Chornay","full_name":"Chornay, Nicholas","first_name":"Nicholas"},{"last_name":"Graham","full_name":"Graham, Matthew J.","first_name":"Matthew J."},{"last_name":"Rodriguez","full_name":"Rodriguez, Antonio C.","first_name":"Antonio C."},{"full_name":"Zeimann, Gregory R.","first_name":"Gregory R.","last_name":"Zeimann"},{"first_name":"Christoffer","full_name":"Fremling, Christoffer","last_name":"Fremling"},{"first_name":"Andrew J.","full_name":"Drake, Andrew J.","last_name":"Drake"},{"last_name":"Werner","first_name":"Klaus","full_name":"Werner, Klaus"},{"full_name":"Rodriguez, Hector","first_name":"Hector","last_name":"Rodriguez"},{"last_name":"Prince","first_name":"Thomas A.","full_name":"Prince, Thomas A."},{"last_name":"Laher","full_name":"Laher, Russ R.","first_name":"Russ R."},{"full_name":"Chen, Tracy X.","first_name":"Tracy X.","last_name":"Chen"},{"last_name":"Riddle","first_name":"Reed","full_name":"Riddle, Reed"}],"language":[{"iso":"eng"}],"title":"Variability of central stars of planetary nebulae with the zwicky transient facility. I. Methods, short-timescale variables, and the unusual nucleus of WeSb 1","quality_controlled":"1","tmp":{"name":"Creative Commons Attribution 3.0 Unported (CC BY 3.0)","short":"CC BY (3.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/3.0/legalcode"}},{"department":[{"_id":"IlCa"}],"citation":{"ieee":"A. C. Rodriguez <i>et al.</i>, “A link between White Dwarf pulsars and polars: Multiwavelength observations of the 9.36-minute period variable Gaia22ayj,” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 2. IOP Publishing, 2025.","chicago":"Rodriguez, Antonio C., Kareem El-Badry, Pasi Hakala, Pablo Rodríguez-Gil, Tong Bao, Ilkham Galiullin, Jacob A. Kurlander, et al. “A Link between White Dwarf Pulsars and Polars: Multiwavelength Observations of the 9.36-Minute Period Variable Gaia22ayj.” <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.1088/1538-3873/adb0f1\">https://doi.org/10.1088/1538-3873/adb0f1</a>.","mla":"Rodriguez, Antonio C., et al. “A Link between White Dwarf Pulsars and Polars: Multiwavelength Observations of the 9.36-Minute Period Variable Gaia22ayj.” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 2, 024202, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.1088/1538-3873/adb0f1\">10.1088/1538-3873/adb0f1</a>.","ama":"Rodriguez AC, El-Badry K, Hakala P, et al. A link between White Dwarf pulsars and polars: Multiwavelength observations of the 9.36-minute period variable Gaia22ayj. <i>Publications of the Astronomical Society of the Pacific</i>. 2025;137(2). doi:<a href=\"https://doi.org/10.1088/1538-3873/adb0f1\">10.1088/1538-3873/adb0f1</a>","short":"A.C. Rodriguez, K. El-Badry, P. Hakala, P. Rodríguez-Gil, T. Bao, I. Galiullin, J.A. Kurlander, C.J. Law, I. Pelisoli, M.R. Schreiber, K. Burdge, I. Caiazzo, J.V. Roestel, P. Szkody, A.J. Drake, D.A.H. Buckley, S.B. Potter, B. Gaensicke, K. Mori, E.C. Bellm, S.R. Kulkarni, T.A. Prince, M. Graham, M.M. Kasliwal, S. Rose, Y. Sharma, T. Ahumada, S. Anand, A. Viitanen, A. Wold, T.X. Chen, R. Riddle, R. Smith, Publications of the Astronomical Society of the Pacific 137 (2025).","ista":"Rodriguez AC, El-Badry K, Hakala P, Rodríguez-Gil P, Bao T, Galiullin I, Kurlander JA, Law CJ, Pelisoli I, Schreiber MR, Burdge K, Caiazzo I, Roestel JV, Szkody P, Drake AJ, Buckley DAH, Potter SB, Gaensicke B, Mori K, Bellm EC, Kulkarni SR, Prince TA, Graham M, Kasliwal MM, Rose S, Sharma Y, Ahumada T, Anand S, Viitanen A, Wold A, Chen TX, Riddle R, Smith R. 2025. A link between White Dwarf pulsars and polars: Multiwavelength observations of the 9.36-minute period variable Gaia22ayj. Publications of the Astronomical Society of the Pacific. 137(2), 024202.","apa":"Rodriguez, A. C., El-Badry, K., Hakala, P., Rodríguez-Gil, P., Bao, T., Galiullin, I., … Smith, R. (2025). A link between White Dwarf pulsars and polars: Multiwavelength observations of the 9.36-minute period variable Gaia22ayj. <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing. <a href=\"https://doi.org/10.1088/1538-3873/adb0f1\">https://doi.org/10.1088/1538-3873/adb0f1</a>"},"type":"journal_article","oa":1,"doi":"10.1088/1538-3873/adb0f1","acknowledgement":"We wish to dedicate this work to the memory of our colleague and friend Tom Marsh. Tom's enthusiasm to work on this object and rapid efforts to facilitate data collection truly made this project possible.\r\n\r\nA.C.R. acknowledges support from an NSF Graduate Fellowship. A.C.R. thanks the LSST-DA Data Science Fellowship Program, which is funded by LSST-DA, the Brinson Foundation, and the Moore Foundation; his participation in the program has benefited this work. P.R.-G. acknowledges support by the Spanish Agencia Estatal de Investigación del Ministerio de Ciencia e Innovación (MCIN/AEI) and the European Regional Development Fund (ERDF) under grant PID2021–124879NB–I00. M.R.S. is supported by FONDECYT (grant No. 1221059) and eRO-STEP (SA 2131/15-2 project number 414059771). I.P. acknowledges support from a Royal Society University Research Fellowship (URF/R1/231496). We thank the referee for feedback that improved the clarity of this paper.\r\n\r\nBased on observations made with the Gran Telescopio Canarias (GTC), installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofìsica de Canarias, on the island of La Palma. Based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the ZTF project. ZTF is supported by the National Science Foundation under grants No. AST-1440341 and AST-2034437 and a collaboration including current partners Caltech, IPAC, the Weizmann Institute of Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, IN2P3, University of Warwick, Ruhr University Bochum, Northwestern University and former partners the University of Washington, Los Alamos National Laboratories, and Lawrence Berkeley National Laboratories. Operations are conducted by COO, IPAC, and UW.\r\n\r\nSome of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. We are also grateful to the staff of Palomar Observatory for their assistance in carrying out observations used in this work.\r\n\r\nPartly based on observations made with the NOT, owned in collaboration by the University of Turku and Aarhus University, and operated jointly by Aarhus University, the University of Turku and the University of Oslo, representing Denmark, Finland and Norway, the University of Iceland and Stockholm University at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. The data presented here were obtained with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOT. The observation with the SALT was obtained under program 2021-2-LSP-001 (PI: D. Buckley). Polish participation in SALT is funded by grant No. MEiN nr 2021/WK/01. D.A.H.B. acknowledges support from the National Research Foundation.\r\n\r\nThis work presents results from the European Space Agency (ESA) space mission Gaia. Gaia data are being processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC is provided by national institutions, in particular the institutions participating in the Gaia MultiLateral Agreement (MLA). The Gaia mission website is https://www.cosmos.esa.int/gaia. The Gaia archive website is https://archives.esac.esa.int/gaia. This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester\r\n\r\nE.C.B. and J.K. acknowledge support from the DIRAC Institute in the Department of Astronomy at the University of Washington. The DIRAC Institute is supported through generous gifts from the Charles and Lisa Simonyi Fund for Arts and Sciences, and the Washington Research Foundation.","publication_identifier":{"issn":["0004-6280"]},"day":"01","_id":"19439","publication":"Publications of the Astronomical Society of the Pacific","file_date_updated":"2025-03-25T10:01:24Z","issue":"2","date_published":"2025-02-01T00:00:00Z","publisher":"IOP Publishing","arxiv":1,"date_updated":"2025-09-30T11:15:10Z","isi":1,"month":"02","year":"2025","abstract":[{"lang":"eng","text":"White dwarfs (WDs) are the most abundant compact objects, and recent surveys have suggested that over a third of WDs in accreting binaries host a strong (B  ≳ 1 MG) magnetic field. However, the origin and evolution of WD magnetism remain under debate. Two WD pulsars, AR Sco and J191213.72–441045.1 (J1912), have been found, which are non-accreting binaries hosting rapidly spinning (1.97 minutes and 5.30 minutes, respectively) magnetic WDs. The WD in AR Sco is slowing down on a (math formular) yr timescale. It is believed they will eventually become polars, accreting systems in which a magnetic WD (B  ≈ 10−240 MG) accretes from a Roche lobe-filling donor spinning in sync with the orbit (≳78 minutes). Here, we present multiwavelength data and analysis of Gaia22ayj, which outbursted in 2022 March. We find that Gaia22ayj is a magnetic accreting WD that is rapidly spinning down (math formular\r\n yr) like WD pulsars, but shows clear evidence of accretion, like polars. Strong linear polarization (40%) is detected in Gaia22ayj; such high levels have only been seen in the WD pulsar AR Sco and demonstrate the WD is magnetic. High speed photometry reveals a 9.36 minutes period accompanying a high amplitude (∼2 mag) modulation. We associate this with a WD spin or spin–orbit beat period, not an orbital period as was previously suggested. Fast (60 s) optical spectroscopy reveals a broad \"hump,\" reminiscent of cyclotron emission in polars, between 4000 and 8000 Å. We find an X-ray luminosity of (math formular) in the 0.3–8 keV energy range, while two very large array radio campaigns resulted in a non-detection with a Fr < 15.8 μJy 3σ upper limit. The shared properties of both WD pulsars and polars suggest that Gaia22ayj is a missing link between the two classes of magnetic WD binaries."}],"scopus_import":"1","file":[{"date_updated":"2025-03-25T10:01:24Z","success":1,"file_size":3291933,"file_name":"2025_PubAstronomSocPacific_Rodriguez.pdf","checksum":"42d5aa504479c3fdf2a10165a9e3319f","content_type":"application/pdf","date_created":"2025-03-25T10:01:24Z","relation":"main_file","access_level":"open_access","creator":"dernst","file_id":"19455"}],"oa_version":"Published Version","article_processing_charge":"Yes (in subscription journal)","OA_place":"publisher","publication_status":"published","language":[{"iso":"eng"}],"author":[{"first_name":"Antonio C.","full_name":"Rodriguez, Antonio C.","last_name":"Rodriguez"},{"first_name":"Kareem","full_name":"El-Badry, Kareem","last_name":"El-Badry"},{"last_name":"Hakala","full_name":"Hakala, Pasi","first_name":"Pasi"},{"full_name":"Rodríguez-Gil, Pablo","first_name":"Pablo","last_name":"Rodríguez-Gil"},{"last_name":"Bao","first_name":"Tong","full_name":"Bao, Tong"},{"last_name":"Galiullin","full_name":"Galiullin, Ilkham","first_name":"Ilkham"},{"first_name":"Jacob A.","full_name":"Kurlander, Jacob A.","last_name":"Kurlander"},{"last_name":"Law","full_name":"Law, Casey J.","first_name":"Casey J."},{"last_name":"Pelisoli","full_name":"Pelisoli, Ingrid","first_name":"Ingrid"},{"first_name":"Matthias R.","full_name":"Schreiber, Matthias R.","last_name":"Schreiber"},{"last_name":"Burdge","full_name":"Burdge, Kevin","first_name":"Kevin"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","first_name":"Ilaria","full_name":"Caiazzo, Ilaria","last_name":"Caiazzo","orcid":"0000-0002-4770-5388"},{"full_name":"Roestel, Jan Van","first_name":"Jan Van","last_name":"Roestel"},{"last_name":"Szkody","full_name":"Szkody, Paula","first_name":"Paula"},{"last_name":"Drake","first_name":"Andrew J.","full_name":"Drake, Andrew J."},{"first_name":"David A.H.","full_name":"Buckley, David A.H.","last_name":"Buckley"},{"full_name":"Potter, Stephen B.","first_name":"Stephen B.","last_name":"Potter"},{"last_name":"Gaensicke","first_name":"Boris","full_name":"Gaensicke, Boris"},{"full_name":"Mori, Kaya","first_name":"Kaya","last_name":"Mori"},{"first_name":"Eric C.","full_name":"Bellm, Eric C.","last_name":"Bellm"},{"first_name":"Shrinivas R.","full_name":"Kulkarni, Shrinivas R.","last_name":"Kulkarni"},{"first_name":"Thomas A.","full_name":"Prince, Thomas A.","last_name":"Prince"},{"last_name":"Graham","full_name":"Graham, Matthew","first_name":"Matthew"},{"last_name":"Kasliwal","first_name":"Mansi M.","full_name":"Kasliwal, Mansi M."},{"last_name":"Rose","first_name":"Sam","full_name":"Rose, Sam"},{"first_name":"Yashvi","full_name":"Sharma, Yashvi","last_name":"Sharma"},{"first_name":"Tomás","full_name":"Ahumada, Tomás","last_name":"Ahumada"},{"last_name":"Anand","full_name":"Anand, Shreya","first_name":"Shreya"},{"last_name":"Viitanen","first_name":"Akke","full_name":"Viitanen, Akke"},{"last_name":"Wold","first_name":"Avery","full_name":"Wold, Avery"},{"first_name":"Tracy X.","full_name":"Chen, Tracy X.","last_name":"Chen"},{"last_name":"Riddle","first_name":"Reed","full_name":"Riddle, Reed"},{"last_name":"Smith","full_name":"Smith, Roger","first_name":"Roger"}],"external_id":{"isi":["001427877700001"],"arxiv":["2501.01490"]},"status":"public","intvolume":"       137","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"quality_controlled":"1","title":"A link between White Dwarf pulsars and polars: Multiwavelength observations of the 9.36-minute period variable Gaia22ayj","OA_type":"hybrid","has_accepted_license":"1","volume":137,"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","article_number":"024202","date_created":"2025-03-23T23:01:26Z","ddc":["520"],"article_type":"original"},{"publication_identifier":{"issn":["1538-3873"]},"acknowledgement":"This work is based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. Z.T.F. is supported by the National Science Foundation under grants No. AST-1440341 and AST-2034437 and a collaboration including current partners Caltech, IPAC, the Oskar Klein Center at Stockholm University, the University of Maryland, University of California, Berkeley, the University of Wisconsin at Milwaukee, University of Warwick, Ruhr University Bochum, Cornell University, Northwestern University, and Drexel University. Operations are conducted by COO, IPAC, and UW.\r\n\r\nThis work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular, the institutions participating in the Gaia Multilateral Agreement. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration.\r\n\r\nThis research has made use of the VizieR catalog access tool, CDS, Strasbourg, France https://vizier.cds.unistra.fr/. The original description of the VizieR service was published in Ochsenbein et al. (2000).\r\n\r\nWe are grateful to the staffs of Palomar and Keck Observatory for assistance with the observations and data management.\r\n\r\nThe authors thank the anonymous referee for very extensive and useful comments which improved the presentation of the paper significantly. S.B. acknowledges the support from the Kishore Vaigyanik Protsahan Yojana (KVPY) scheme of the Department of Science and Technology, Government of India (a former fellowship program for undergraduate studies in basic science) during his undergraduate studies at IISc. S.B. thanks the Summer Undergraduate Research Fellowship (SURF) at Caltech and Shrinivas R. Kulkarni for hosting him as a summer research student in 2022. S.B. acknowledges the financial support from the Wallace L. W. Sargent Graduate Fellowship during the first year of his graduate studies at Caltech. P.E.T. received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program number 101002408. S.X. is supported by NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. J.A.G. is supported by the National Science Foundation Graduate Research Fellowship Program under grant No. 2234657. This material is based upon work supported by the National Aeronautics and Space Administration under grant No. 80NSSC23K1068 issued through the Science Mission Directorate.\r\n\r\nWe have used Python packages Numpy (Harris et al. 2020), SciPy (Virtanen et al. 2020), Matplotlib (Hunter 2007), Pandas (The pandas development team 2020), Astropy (Astropy Collaboration et al. 2013, 2018), and Astroquery (Ginsburg et al. 2019) at various stages of this research.","doi":"10.1088/1538-3873/ade0ea","oa":1,"citation":{"chicago":"Bhattacharjee, Soumyadeep , Zachary P. Vanderbosch, Mark A. Hollands, Pier-Emmanuel Tremblay, Siyi Xu, Joseph A. Guidry, J.J. Hermes, et al. “A ZTF Search for Circumstellar Debris Transits in White Dwarfs: Six New Candidates, One with Gas Disk Emission, Identified in a Novel Metric Space.” <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.1088/1538-3873/ade0ea\">https://doi.org/10.1088/1538-3873/ade0ea</a>.","ieee":"S. Bhattacharjee <i>et al.</i>, “A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space,” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 7. IOP Publishing, 2025.","apa":"Bhattacharjee, S., Vanderbosch, Z. P., Hollands, M. A., Tremblay, P.-E., Xu, S., Guidry, J. A., … Toloza, O. (2025). A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space. <i>Publications of the Astronomical Society of the Pacific</i>. IOP Publishing. <a href=\"https://doi.org/10.1088/1538-3873/ade0ea\">https://doi.org/10.1088/1538-3873/ade0ea</a>","ista":"Bhattacharjee S, Vanderbosch ZP, Hollands MA, Tremblay P-E, Xu S, Guidry JA, Hermes JJ, Caiazzo I, Rodriguez AC, van Roestel J, El-Badry K, Drake AJ, Roulston BR, Riddle R, Rusholme B, Groom SL, Smith R, Toloza O. 2025. A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space. Publications of the Astronomical Society of the Pacific. 137(7), 074202.","short":"S. Bhattacharjee, Z.P. Vanderbosch, M.A. Hollands, P.-E. Tremblay, S. Xu, J.A. Guidry, J.J. Hermes, I. Caiazzo, A.C. Rodriguez, J. van Roestel, K. El-Badry, A.J. Drake, B.R. Roulston, R. Riddle, B. Rusholme, S.L. Groom, R. Smith, O. Toloza, Publications of the Astronomical Society of the Pacific 137 (2025).","mla":"Bhattacharjee, Soumyadeep, et al. “A ZTF Search for Circumstellar Debris Transits in White Dwarfs: Six New Candidates, One with Gas Disk Emission, Identified in a Novel Metric Space.” <i>Publications of the Astronomical Society of the Pacific</i>, vol. 137, no. 7, 074202, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.1088/1538-3873/ade0ea\">10.1088/1538-3873/ade0ea</a>.","ama":"Bhattacharjee S, Vanderbosch ZP, Hollands MA, et al. A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space. <i>Publications of the Astronomical Society of the Pacific</i>. 2025;137(7). doi:<a href=\"https://doi.org/10.1088/1538-3873/ade0ea\">10.1088/1538-3873/ade0ea</a>"},"department":[{"_id":"IlCa"}],"type":"journal_article","issue":"7","file_date_updated":"2026-02-17T11:30:29Z","publication":"Publications of the Astronomical Society of the Pacific","day":"09","_id":"21241","year":"2025","abstract":[{"lang":"eng","text":"White dwarfs (WDs) showing transits from orbiting planetary debris provide significant insights into the structure and dynamics of debris disks, which are eventually accreted to produce metal pollution. This is a rare class of objects with only eight published systems. In this work, we perform a systematic search for such systems within 500 pc in the Gaia-eDR3 catalog of WDs using the light curves from the Zwicky Transient Facility (ZTF) and present six new candidates. Our selection process targets the top 1% most photometrically variable sources identified using a combined variability metric from ZTF and Gaia eDR3 photometry, boosted by a metric space we define using von Neumann statistics and Pearson-Skew as a novel discovery tool to identify these systems. This is followed by optical spectroscopic observations of visually selected variables to confirm metal pollution. Four of the six systems show long-timescale photometric variability spanning several months to years, resulting either from long-term evolution of transit activity or dust and debris clouds at wide orbits. Among them, WD J1013–0427 shows an indication of reddening during the long-duration dip. Interpreting this as dust extinction makes it the first system to indicate an abundance of dust grains with radius ≲0.3 μm in the occulting material. The same object also shows metal emission lines that map an optically thick eccentric gas disk orbiting within the star’s Roche limit. For each candidate, we infer the abundances of the photospheric metals and estimate accretion rates. We show that transiting debris systems tend to have higher inferred accretion rates compared to the general population of metal-polluted WDs. Growing the number of these systems will further illuminate such comparative properties in the near future. Separately, we also serendipitously discovered an AM Canis Venaticorum showing a very long-duration outburst—only the fourth such system to be known."}],"month":"07","date_updated":"2026-02-17T11:35:53Z","arxiv":1,"publisher":"IOP Publishing","date_published":"2025-07-09T00:00:00Z","OA_place":"publisher","publication_status":"published","article_processing_charge":"Yes (in subscription journal)","oa_version":"Published Version","file":[{"file_id":"21289","access_level":"open_access","creator":"dernst","date_created":"2026-02-17T11:30:29Z","relation":"main_file","content_type":"application/pdf","file_name":"2025_PASP_Bhattacharjee.pdf","checksum":"237eddc36e3823b3092fab6aa5bc8655","file_size":8900420,"success":1,"date_updated":"2026-02-17T11:30:29Z"}],"intvolume":"       137","status":"public","external_id":{"arxiv":["2502.05502"]},"author":[{"last_name":"Bhattacharjee","full_name":"Bhattacharjee, Soumyadeep ","first_name":"Soumyadeep "},{"first_name":"Zachary P.","full_name":"Vanderbosch, Zachary P.","last_name":"Vanderbosch"},{"full_name":"Hollands, Mark A.","first_name":"Mark A.","last_name":"Hollands"},{"last_name":"Tremblay","full_name":"Tremblay, Pier-Emmanuel","first_name":"Pier-Emmanuel"},{"last_name":"Xu","first_name":"Siyi","full_name":"Xu, Siyi"},{"last_name":"Guidry","full_name":"Guidry, Joseph A.","first_name":"Joseph A."},{"full_name":"Hermes, J.J.","first_name":"J.J.","last_name":"Hermes"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","orcid":"0000-0002-4770-5388","last_name":"Caiazzo","first_name":"Ilaria","full_name":"Caiazzo, Ilaria"},{"full_name":"Rodriguez, Antonio C.","first_name":"Antonio C.","last_name":"Rodriguez"},{"last_name":"van Roestel","full_name":"van Roestel, Jan","first_name":"Jan"},{"last_name":"El-Badry","full_name":"El-Badry, Kareem ","first_name":"Kareem "},{"last_name":"Drake","first_name":"Andrew J.","full_name":"Drake, Andrew J."},{"full_name":"Roulston, Benjamin R.","first_name":"Benjamin R.","last_name":"Roulston"},{"last_name":"Riddle","first_name":"Reed","full_name":"Riddle, Reed"},{"last_name":"Rusholme","full_name":"Rusholme, Ben","first_name":"Ben"},{"first_name":"Steven L.","full_name":"Groom, Steven L.","last_name":"Groom"},{"full_name":"Smith, Roger","first_name":"Roger","last_name":"Smith"},{"full_name":"Toloza, Odette","first_name":"Odette","last_name":"Toloza"}],"language":[{"iso":"eng"}],"title":"A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space","quality_controlled":"1","tmp":{"name":"Creative Commons Attribution 3.0 Unported (CC BY 3.0)","short":"CC BY (3.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/3.0/legalcode"},"volume":137,"has_accepted_license":"1","OA_type":"hybrid","article_type":"original","ddc":["520"],"date_created":"2026-02-16T15:10:51Z","PlanS_conform":"1","article_number":"074202","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87"},{"year":"2025","abstract":[{"lang":"eng","text":"Accreting white dwarfs (WDs) in close binary systems, commonly known as cataclysmic variables (CVs), with orbital periods below the canonical period minimum (≈80 minutes) are rare. Such short periods can only be reached if the donor star in the CV is either significantly evolved before initiating mass transfer to the WD or is metal-poor. We present optical photometry and spectroscopy of Gaia19bxc, a high-amplitude variable identified as a polar CV with an exceptionally short orbital period of 64.42 minutes—well below the canonical CV period minimum. High-speed photometry confirms persistent double-peaked variability consistent with cyclotron beaming, thus indicating the presence of a magnetic WD. Phase-resolved Keck/Low-Resolution Imaging Spectrometer (LRIS) spectroscopy reveals strong hydrogen and helium emission lines but no donor features, indicating the accretor is a magnetic WD and the donor is hydrogen-rich, but cold and faint. The absence of a detectable donor and the low inferred temperature (≲3500 K) disfavor an evolved donor scenario. Instead, the short period and the system’s halo-like kinematics suggest Gaia19bxc may be the first known metal-poor polar. Because metal-poor donors are more compact than solar-metallicity donors of the same mass, they can reach shorter minimum periods. Gaia19bxc is one of only a handful of known metal-poor CVs below the canonical period minimum and has the shortest period of any such magnetic system discovered to date."}],"scopus_import":"1","arxiv":1,"date_updated":"2026-02-19T07:27:01Z","month":"09","date_published":"2025-09-08T00:00:00Z","publisher":"IOP Publishing","OA_place":"publisher","publication_status":"published","article_processing_charge":"Yes","file":[{"content_type":"application/pdf","file_name":"2025_AstrophysicalJournal_Galiullin.pdf","checksum":"f76556d129aa0e9facc85602b0b5b54d","file_size":3772189,"date_updated":"2026-02-19T07:24:10Z","success":1,"file_id":"21329","access_level":"open_access","creator":"dernst","date_created":"2026-02-19T07:24:10Z","relation":"main_file"}],"oa_version":"Published Version","doi":"10.3847/2041-8213/adff82","acknowledgement":"Based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under grants No. AST-1440341 and AST-2034437 and a collaboration including current partners Caltech, IPAC, the Weizmann Institute of Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, IN2P3, University of Warwick, Ruhr University Bochum, Northwestern University and former partners the University of Washington, Los Alamos National Laboratories, and Lawrence Berkeley National Laboratories. Operations are conducted by COO, IPAC, and UW. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 nonprofit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. We wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have had the opportunity to conduct observations from this mountain. We are grateful to the staff of the Palomar and Keck Observatories for their work in helping us carry out our observations.\r\n\r\nI.G. acknowledges support from Kazan Federal University. A.C.R. acknowledges support from the National Science Foundation via an NSF Graduate Research Fellowship. We thank the anonymous referee for useful comments and suggestions, which contributed to the improvement of this manuscript.","publication_identifier":{"issn":["2041-8205"],"eissn":["2041-8213"]},"oa":1,"type":"journal_article","department":[{"_id":"IlCa"}],"citation":{"ieee":"I. Galiullin <i>et al.</i>, “Optical spectroscopy of the most compact accreting binary harboring a magnetic White Dwarf and a hydrogen-rich donor,” <i>The Astrophysical Journal Letters</i>, vol. 990, no. 2. IOP Publishing, 2025.","chicago":"Galiullin, Ilkham, Antonio C. Rodriguez, Kareem El-Badry, Ilaria Caiazzo, Paula Szkody, Pranav Nagarajan, and Samuel Whitebook. “Optical Spectroscopy of the Most Compact Accreting Binary Harboring a Magnetic White Dwarf and a Hydrogen-Rich Donor.” <i>The Astrophysical Journal Letters</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.3847/2041-8213/adff82\">https://doi.org/10.3847/2041-8213/adff82</a>.","ama":"Galiullin I, Rodriguez AC, El-Badry K, et al. Optical spectroscopy of the most compact accreting binary harboring a magnetic White Dwarf and a hydrogen-rich donor. <i>The Astrophysical Journal Letters</i>. 2025;990(2). doi:<a href=\"https://doi.org/10.3847/2041-8213/adff82\">10.3847/2041-8213/adff82</a>","mla":"Galiullin, Ilkham, et al. “Optical Spectroscopy of the Most Compact Accreting Binary Harboring a Magnetic White Dwarf and a Hydrogen-Rich Donor.” <i>The Astrophysical Journal Letters</i>, vol. 990, no. 2, L57, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.3847/2041-8213/adff82\">10.3847/2041-8213/adff82</a>.","short":"I. Galiullin, A.C. Rodriguez, K. El-Badry, I. Caiazzo, P. Szkody, P. Nagarajan, S. Whitebook, The Astrophysical Journal Letters 990 (2025).","ista":"Galiullin I, Rodriguez AC, El-Badry K, Caiazzo I, Szkody P, Nagarajan P, Whitebook S. 2025. Optical spectroscopy of the most compact accreting binary harboring a magnetic White Dwarf and a hydrogen-rich donor. The Astrophysical Journal Letters. 990(2), L57.","apa":"Galiullin, I., Rodriguez, A. C., El-Badry, K., Caiazzo, I., Szkody, P., Nagarajan, P., &#38; Whitebook, S. (2025). Optical spectroscopy of the most compact accreting binary harboring a magnetic White Dwarf and a hydrogen-rich donor. <i>The Astrophysical Journal Letters</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/2041-8213/adff82\">https://doi.org/10.3847/2041-8213/adff82</a>"},"file_date_updated":"2026-02-19T07:24:10Z","issue":"2","publication":"The Astrophysical Journal Letters","day":"08","_id":"21317","volume":990,"has_accepted_license":"1","OA_type":"gold","article_type":"original","date_created":"2026-02-18T10:17:04Z","ddc":["520"],"article_number":"L57","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","PlanS_conform":"1","intvolume":"       990","status":"public","language":[{"iso":"eng"}],"external_id":{"arxiv":["2508.20170"]},"author":[{"last_name":"Galiullin","full_name":"Galiullin, Ilkham","first_name":"Ilkham"},{"full_name":"Rodriguez, Antonio C.","first_name":"Antonio C.","last_name":"Rodriguez"},{"last_name":"El-Badry","full_name":"El-Badry, Kareem","first_name":"Kareem"},{"full_name":"Caiazzo, Ilaria","first_name":"Ilaria","orcid":"0000-0002-4770-5388","last_name":"Caiazzo","id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d"},{"last_name":"Szkody","full_name":"Szkody, Paula","first_name":"Paula"},{"first_name":"Pranav","full_name":"Nagarajan, Pranav","last_name":"Nagarajan"},{"first_name":"Samuel","full_name":"Whitebook, Samuel","last_name":"Whitebook"}],"quality_controlled":"1","title":"Optical spectroscopy of the most compact accreting binary harboring a magnetic White Dwarf and a hydrogen-rich donor","tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"DOAJ_listed":"1"}]