{"volume":706,"oa":1,"ddc":["520"],"date_created":"2026-02-08T23:02:49Z","department":[{"_id":"IlCa"}],"_id":"21160","publication":"Astronomy and Astrophysics","arxiv":1,"file_date_updated":"2026-02-16T09:33:56Z","article_number":"A14","date_updated":"2026-02-16T09:36:24Z","citation":{"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.","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>.","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>","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).","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.","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>","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>."},"scopus_import":"1","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).","OA_type":"diamond","status":"public","quality_controlled":"1","abstract":[{"lang":"eng","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."}],"month":"02","has_accepted_license":"1","article_type":"original","external_id":{"arxiv":["2512.04147"]},"intvolume":"       706","year":"2026","doi":"10.1051/0004-6361/202557568","publisher":"EDP Sciences","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"OA_place":"publisher","publication_status":"published","type":"journal_article","author":[{"full_name":"Yu, W.","first_name":"W.","last_name":"Yu"},{"last_name":"Pala","full_name":"Pala, A. F.","first_name":"A. F."},{"last_name":"Kupfer","full_name":"Kupfer, T.","first_name":"T."},{"first_name":"B. T.","full_name":"Gänsicke, B. T.","last_name":"Gänsicke"},{"full_name":"Koester, D.","first_name":"D.","last_name":"Koester"},{"last_name":"Belloni","full_name":"Belloni, D.","first_name":"D."},{"first_name":"T. L.S.","full_name":"Wong, T. L.S.","last_name":"Wong"},{"first_name":"M. R.","full_name":"Schreiber, M. R.","last_name":"Schreiber"},{"first_name":"Joannes C","full_name":"van Roestel, Joannes C","last_name":"van Roestel","id":"4d122fc8-6083-11f0-87a5-97d68b860333"},{"first_name":"A. J.","full_name":"Brown, A. J.","last_name":"Brown"},{"last_name":"Waagen","first_name":"E. O.","full_name":"Waagen, E. O."},{"full_name":"González-Carballo, J. L.","first_name":"J. L.","last_name":"González-Carballo"},{"first_name":"S.","full_name":"Bednarz, S.","last_name":"Bednarz"},{"last_name":"Bernacki","first_name":"K.","full_name":"Bernacki, K."},{"first_name":"D.","full_name":"De Martino, D.","last_name":"De Martino"},{"full_name":"Fernández Mañanes, E.","first_name":"E.","last_name":"Fernández Mañanes"},{"last_name":"González Farfán","first_name":"R.","full_name":"González Farfán, R."},{"last_name":"Green","first_name":"M. J.","full_name":"Green, M. J."},{"last_name":"Groot","first_name":"P. J.","full_name":"Groot, P. J."},{"first_name":"F. J.","full_name":"Hambsch, F. J.","last_name":"Hambsch"},{"last_name":"Knigge","full_name":"Knigge, C.","first_name":"C."},{"last_name":"Martin-Velasco","full_name":"Martin-Velasco, J. L.","first_name":"J. L."},{"last_name":"Morales-Aimar","full_name":"Morales-Aimar, M.","first_name":"M."},{"full_name":"Myers, G.","first_name":"G.","last_name":"Myers"},{"full_name":"Naves Nogues, R.","first_name":"R.","last_name":"Naves Nogues"},{"last_name":"Poggiani","full_name":"Poggiani, R.","first_name":"R."},{"last_name":"Popowicz","full_name":"Popowicz, A.","first_name":"A."},{"full_name":"Ramsay, G.","first_name":"G.","last_name":"Ramsay"},{"first_name":"E.","full_name":"Reina-Lorenz, E.","last_name":"Reina-Lorenz"},{"last_name":"Rodríguez-Gil","first_name":"P.","full_name":"Rodríguez-Gil, P."},{"first_name":"J. L.","full_name":"Salto-González, J. L.","last_name":"Salto-González"},{"last_name":"Sion","first_name":"E. M.","full_name":"Sion, E. M."},{"last_name":"Steeghs","full_name":"Steeghs, D.","first_name":"D."},{"full_name":"Szkody, P.","first_name":"P.","last_name":"Szkody"},{"last_name":"Toloza","first_name":"O.","full_name":"Toloza, O."},{"full_name":"Tovmassian, G.","first_name":"G.","last_name":"Tovmassian"}],"file":[{"file_size":4020466,"creator":"dernst","content_type":"application/pdf","access_level":"open_access","success":1,"date_updated":"2026-02-16T09:33:56Z","file_id":"21227","relation":"main_file","file_name":"2026_AstronomyAstrophysics_Yu.pdf","checksum":"2faec710fd04f927aa43deb57e35c9b2","date_created":"2026-02-16T09:33:56Z"}],"tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png"},"PlanS_conform":"1","publication_identifier":{"issn":["0004-6361"],"eissn":["1432-0746"]},"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","article_processing_charge":"No","oa_version":"Published Version","license":"https://creativecommons.org/licenses/by/4.0/","day":"01","date_published":"2026-02-01T00:00:00Z"}