---
OA_place: publisher
OA_type: diamond
PlanS_conform: '1'
_id: '21160'
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."
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)."
article_number: A14
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: W.
full_name: Yu, W.
last_name: Yu
- first_name: A. F.
full_name: Pala, A. F.
last_name: Pala
- first_name: T.
full_name: Kupfer, T.
last_name: Kupfer
- first_name: B. T.
full_name: Gänsicke, B. T.
last_name: Gänsicke
- first_name: D.
full_name: Koester, D.
last_name: Koester
- first_name: D.
full_name: Belloni, D.
last_name: Belloni
- 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
id: 4d122fc8-6083-11f0-87a5-97d68b860333
last_name: van Roestel
- first_name: A. J.
full_name: Brown, A. J.
last_name: Brown
- first_name: E. O.
full_name: Waagen, E. O.
last_name: Waagen
- first_name: J. L.
full_name: González-Carballo, J. L.
last_name: González-Carballo
- first_name: S.
full_name: Bednarz, S.
last_name: Bednarz
- first_name: K.
full_name: Bernacki, K.
last_name: Bernacki
- first_name: D.
full_name: De Martino, D.
last_name: De Martino
- first_name: E.
full_name: Fernández Mañanes, E.
last_name: Fernández Mañanes
- first_name: R.
full_name: González Farfán, R.
last_name: González Farfán
- first_name: M. J.
full_name: Green, M. J.
last_name: Green
- first_name: P. J.
full_name: Groot, P. J.
last_name: Groot
- first_name: F. J.
full_name: Hambsch, F. J.
last_name: Hambsch
- first_name: C.
full_name: Knigge, C.
last_name: Knigge
- first_name: J. L.
full_name: Martin-Velasco, J. L.
last_name: Martin-Velasco
- first_name: M.
full_name: Morales-Aimar, M.
last_name: Morales-Aimar
- first_name: G.
full_name: Myers, G.
last_name: Myers
- first_name: R.
full_name: Naves Nogues, R.
last_name: Naves Nogues
- first_name: R.
full_name: Poggiani, R.
last_name: Poggiani
- first_name: A.
full_name: Popowicz, A.
last_name: Popowicz
- first_name: G.
full_name: Ramsay, G.
last_name: Ramsay
- first_name: E.
full_name: Reina-Lorenz, E.
last_name: Reina-Lorenz
- first_name: P.
full_name: Rodríguez-Gil, P.
last_name: Rodríguez-Gil
- first_name: J. L.
full_name: Salto-González, J. L.
last_name: Salto-González
- first_name: E. M.
full_name: Sion, E. M.
last_name: Sion
- first_name: D.
full_name: Steeghs, D.
last_name: Steeghs
- first_name: P.
full_name: Szkody, P.
last_name: Szkody
- first_name: O.
full_name: Toloza, O.
last_name: Toloza
- first_name: G.
full_name: Tovmassian, G.
last_name: Tovmassian
citation:
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. Astronomy and
Astrophysics. 2026;706. doi:10.1051/0004-6361/202557568'
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. Astronomy and Astrophysics.
EDP Sciences. https://doi.org/10.1051/0004-6361/202557568'
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.” Astronomy and Astrophysics.
EDP Sciences, 2026. https://doi.org/10.1051/0004-6361/202557568.'
ieee: 'W. Yu 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,” Astronomy and Astrophysics,
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.'
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.” Astronomy and Astrophysics,
vol. 706, A14, EDP Sciences, 2026, doi:10.1051/0004-6361/202557568.'
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).
date_created: 2026-02-08T23:02:49Z
date_published: 2026-02-01T00:00:00Z
date_updated: 2026-02-16T09:36:24Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1051/0004-6361/202557568
external_id:
arxiv:
- '2512.04147'
file:
- access_level: open_access
checksum: 2faec710fd04f927aa43deb57e35c9b2
content_type: application/pdf
creator: dernst
date_created: 2026-02-16T09:33:56Z
date_updated: 2026-02-16T09:33:56Z
file_id: '21227'
file_name: 2026_AstronomyAstrophysics_Yu.pdf
file_size: 4020466
relation: main_file
success: 1
file_date_updated: 2026-02-16T09:33:56Z
has_accepted_license: '1'
intvolume: ' 706'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '02'
oa: 1
oa_version: Published Version
publication: Astronomy and Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
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:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 706
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: diamond
PlanS_conform: '1'
_id: '21658'
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.
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).'
article_number: A321
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Bastien Raymond Bernard
full_name: Liagre, Bastien Raymond Bernard
id: 662f1873-cab4-11f0-a719-8087d302868d
last_name: Liagre
- first_name: Aayush A
full_name: Desai, Aayush A
id: 502cfd30-32c1-11ee-a9a4-d8dad5c6739e
last_name: Desai
- first_name: Lukas
full_name: Einramhof, Lukas
id: f1497a1a-72ef-11ef-b75a-fd877bbf6e8c
last_name: Einramhof
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
citation:
ama: 'Liagre BRB, Desai AA, Einramhof L, Bugnet LA. Near-degeneracy effects in quadrupolar
mixed modes: From an asymptotic description to data fitting. Astronomy and
Astrophysics. 2026;707. doi:10.1051/0004-6361/202558023'
apa: 'Liagre, B. R. B., Desai, A. A., Einramhof, L., & Bugnet, L. A. (2026).
Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description
to data fitting. Astronomy and Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/202558023'
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.” Astronomy and Astrophysics.
EDP Sciences, 2026. https://doi.org/10.1051/0004-6361/202558023.'
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,”
Astronomy and Astrophysics, vol. 707. EDP Sciences, 2026.'
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.'
mla: 'Liagre, Bastien Raymond Bernard, et al. “Near-Degeneracy Effects in Quadrupolar
Mixed Modes: From an Asymptotic Description to Data Fitting.” Astronomy and
Astrophysics, vol. 707, A321, EDP Sciences, 2026, doi:10.1051/0004-6361/202558023.'
short: B.R.B. Liagre, A.A. Desai, L. Einramhof, L.A. Bugnet, Astronomy and Astrophysics
707 (2026).
corr_author: '1'
date_created: 2026-04-05T22:01:32Z
date_published: 2026-03-01T00:00:00Z
date_updated: 2026-04-07T09:01:44Z
day: '01'
ddc:
- '520'
department:
- _id: LiBu
- _id: IlCa
- _id: GradSch
doi: 10.1051/0004-6361/202558023
external_id:
arxiv:
- '2511.05314 '
file:
- access_level: open_access
checksum: 560cac19dc70184626b85e71a26ee22e
content_type: application/pdf
creator: dernst
date_created: 2026-04-07T09:00:50Z
date_updated: 2026-04-07T09:00:50Z
file_id: '21664'
file_name: 2026_AstronomyAstrophysics_Liagre.pdf
file_size: 12287607
relation: main_file
success: 1
file_date_updated: 2026-04-07T09:00:50Z
has_accepted_license: '1'
intvolume: ' 707'
language:
- iso: eng
month: '03'
oa: 1
oa_version: Published Version
publication: Astronomy and Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description
to data fitting'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 707
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21725'
abstract:
- lang: eng
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⊙."
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)."
article_number: '69'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: David R.
full_name: Miller, David R.
last_name: Miller
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- 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
- first_name: Pier Emmanuel
full_name: Tremblay, Pier Emmanuel
last_name: Tremblay
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Zachary P.
full_name: Vanderbosch, Zachary P.
last_name: Vanderbosch
citation:
ama: Miller DR, Caiazzo I, Heyl J, et al. The White Dwarf initial–final mass relation
from open clusters in Gaia DR3. The Astrophysical Journal. 2026;996(1).
doi:10.3847/1538-4357/ae18c8
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. The Astrophysical Journal. IOP Publishing.
https://doi.org/10.3847/1538-4357/ae18c8
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.” The Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae18c8.
ieee: D. R. Miller et al., “The White Dwarf initial–final mass relation from
open clusters in Gaia DR3,” The Astrophysical Journal, vol. 996, no. 1.
IOP Publishing, 2026.
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.
mla: Miller, David R., et al. “The White Dwarf Initial–Final Mass Relation from
Open Clusters in Gaia DR3.” The Astrophysical Journal, vol. 996, no. 1,
69, IOP Publishing, 2026, doi:10.3847/1538-4357/ae18c8.
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).
date_created: 2026-04-12T22:01:52Z
date_published: 2026-01-01T00:00:00Z
date_updated: 2026-04-13T08:39:39Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/1538-4357/ae18c8
external_id:
arxiv:
- '2510.24877'
file:
- access_level: open_access
checksum: 65a8237a519188af83b6dc4d47ad85fa
content_type: application/pdf
creator: dernst
date_created: 2026-04-13T08:36:50Z
date_updated: 2026-04-13T08:36:50Z
file_id: '21733'
file_name: 2026_AstrophysicalJournal_Miller.pdf
file_size: 19310053
relation: main_file
success: 1
file_date_updated: 2026-04-13T08:36:50Z
has_accepted_license: '1'
intvolume: ' 996'
issue: '1'
keyword:
- White dwarf stars
- Open star clusters
- Compact objects
- Stellar evolution
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: The White Dwarf initial–final mass relation from open clusters in Gaia DR3
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 996
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21274'
abstract:
- lang: eng
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 ⊙\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 −12\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 −1\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 "
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)."
article_number: A188
article_processing_charge: Yes
article_type: original
author:
- first_name: Andrei-Alexandru
full_name: Cristea, Andrei-Alexandru
id: 4d500bea-31f8-11ee-a48d-d4904fb363c7
last_name: Cristea
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Tim
full_name: Cunningham, Tim
last_name: Cunningham
- first_name: John C.
full_name: Raymond, John C.
last_name: Raymond
- first_name: Stephane
full_name: Vennes, Stephane
last_name: Vennes
- first_name: Adela
full_name: Kawka, Adela
last_name: Kawka
- first_name: Aayush A
full_name: Desai, Aayush A
id: 502cfd30-32c1-11ee-a9a4-d8dad5c6739e
last_name: Desai
- first_name: David R.
full_name: Miller, David R.
last_name: Miller
- first_name: J. J.
full_name: Hermes, J. J.
last_name: Hermes
- first_name: Jim
full_name: Fuller, Jim
last_name: Fuller
- first_name: Jeremy
full_name: Heyl, Jeremy
last_name: Heyl
- first_name: Jan
full_name: van Roestel, Jan
last_name: van Roestel
- first_name: Kevin B.
full_name: Burdge, Kevin B.
last_name: Burdge
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Ingrid
full_name: Pelisoli, Ingrid
last_name: Pelisoli
- first_name: Boris T.
full_name: Gänsicke, Boris T.
last_name: Gänsicke
- first_name: Paula
full_name: Szkody, Paula
last_name: Szkody
- first_name: Scott J.
full_name: Kenyon, Scott J.
last_name: Kenyon
- first_name: Zach
full_name: Vanderbosch, Zach
last_name: Vanderbosch
- first_name: Andrew
full_name: Drake, Andrew
last_name: Drake
- first_name: Lilia
full_name: Ferrario, Lilia
last_name: Ferrario
- first_name: Dayal
full_name: Wickramasinghe, Dayal
last_name: Wickramasinghe
- first_name: Viraj R.
full_name: Karambelkar, Viraj R.
last_name: Karambelkar
- first_name: Stephen
full_name: Justham, Stephen
last_name: Justham
- first_name: Ruediger
full_name: Pakmor, Ruediger
last_name: Pakmor
- first_name: Kareem
full_name: El-Badry, 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
- first_name: Matthew J.
full_name: Graham, Matthew J.
last_name: Graham
- first_name: Frank J.
full_name: Masci, Frank J.
last_name: Masci
- first_name: Steven L.
full_name: Groom, Steven L.
last_name: Groom
- first_name: Josiah
full_name: Purdum, Josiah
last_name: Purdum
- first_name: Richard
full_name: Dekany, Richard
last_name: Dekany
- first_name: Eric C.
full_name: Bellm, Eric C.
last_name: Bellm
citation:
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. Astronomy
& Astrophysics. 2026;706. doi:10.1051/0004-6361/202556432
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. Astronomy & Astrophysics.
EDP Sciences. https://doi.org/10.1051/0004-6361/202556432
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.” Astronomy
& Astrophysics. EDP Sciences, 2026. https://doi.org/10.1051/0004-6361/202556432.
ieee: A.-A. Cristea et al., “A half ring of ionized circumstellar material
trapped in the magnetosphere of a white dwarf merger remnant,” Astronomy &
Astrophysics, vol. 706. EDP Sciences, 2026.
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 & Astrophysics. 706, A188.
mla: Cristea, Andrei-Alexandru, et al. “A Half Ring of Ionized Circumstellar Material
Trapped in the Magnetosphere of a White Dwarf Merger Remnant.” Astronomy &
Astrophysics, vol. 706, A188, EDP Sciences, 2026, doi:10.1051/0004-6361/202556432.
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 & Astrophysics 706 (2026).
corr_author: '1'
date_created: 2026-02-17T08:12:05Z
date_published: 2026-02-10T00:00:00Z
date_updated: 2026-04-28T12:01:21Z
day: '10'
ddc:
- '520'
department:
- _id: IlCa
- _id: GradSch
doi: 10.1051/0004-6361/202556432
file:
- access_level: open_access
checksum: 229b688e6e78cab5bb8e2bac366d1575
content_type: application/pdf
creator: dernst
date_created: 2026-02-23T12:04:37Z
date_updated: 2026-02-23T12:04:37Z
file_id: '21350'
file_name: 2026_AstronomyAstrophysics_Cristea.pdf
file_size: 5352853
relation: main_file
success: 1
file_date_updated: 2026-02-23T12:04:37Z
has_accepted_license: '1'
intvolume: ' 706'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
related_material:
link:
- description: News on ISTA website
relation: press_release
url: https://ista.ac.at/en/news/twos-company-new-class-of-star-remnants/
status: public
title: A half ring of ionized circumstellar material trapped in the magnetosphere
of a white dwarf merger remnant
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 706
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '21705'
abstract:
- lang: eng
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."
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.
article_number: '237'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Emma T.
full_name: Chickles, Emma T.
last_name: Chickles
- first_name: Joheen
full_name: Chakraborty, Joheen
last_name: Chakraborty
- first_name: Kevin B.
full_name: Burdge, Kevin B.
last_name: Burdge
- first_name: Vik S.
full_name: Dhillon, Vik S.
last_name: Dhillon
- first_name: Paul
full_name: Draghis, Paul
last_name: Draghis
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Matthew J.
full_name: Green, Matthew J.
last_name: Green
- first_name: Aaron
full_name: Householder, Aaron
last_name: Householder
- first_name: Sarah
full_name: Hughes, Sarah
last_name: Hughes
- first_name: Christopher
full_name: Layden, Christopher
last_name: Layden
- first_name: Stuart P.
full_name: Littlefair, Stuart P.
last_name: Littlefair
- first_name: James
full_name: Munday, James
last_name: Munday
- first_name: Ingrid
full_name: Pelisoli, Ingrid
last_name: Pelisoli
- first_name: Maya S.
full_name: Redden, Maya S.
last_name: Redden
- first_name: John
full_name: Tonry, John
last_name: Tonry
- first_name: Joannes C
full_name: van Roestel, Joannes C
id: 4d122fc8-6083-11f0-87a5-97d68b860333
last_name: van Roestel
- first_name: Francesco Elio
full_name: Angile, Francesco Elio
last_name: Angile
- first_name: Alex J.
full_name: Brown, Alex J.
last_name: Brown
- first_name: Noel Castro
full_name: Segura, Noel Castro
last_name: Segura
- first_name: Jack
full_name: Dinsmore, Jack
last_name: Dinsmore
- first_name: Martin
full_name: Dyer, Martin
last_name: Dyer
- first_name: Gabor
full_name: Furesz, Gabor
last_name: Furesz
- first_name: Michelle
full_name: Gabutti, Michelle
last_name: Gabutti
- first_name: James
full_name: Garbutt, James
last_name: Garbutt
- first_name: Juliana
full_name: García-Mejía, Juliana
last_name: García-Mejía
- first_name: Daniel
full_name: Jarvis, Daniel
last_name: Jarvis
- first_name: Mark R.
full_name: Kennedy, Mark R.
last_name: Kennedy
- first_name: Paul
full_name: Kerry, Paul
last_name: Kerry
- first_name: James
full_name: Mccormac, James
last_name: Mccormac
- first_name: Geoffrey
full_name: Mo, Geoffrey
last_name: Mo
- first_name: Dave
full_name: Osip, Dave
last_name: Osip
- first_name: Steven
full_name: Parsons, Steven
last_name: Parsons
- first_name: Eleanor
full_name: Pike, Eleanor
last_name: Pike
- first_name: John J.
full_name: Piotrowski, John J.
last_name: Piotrowski
- first_name: Roger W.
full_name: Romani, Roger W.
last_name: Romani
- first_name: David
full_name: Sahman, David
last_name: Sahman
- first_name: Rob
full_name: Simcoe, Rob
last_name: Simcoe
citation:
ama: Chickles ET, Chakraborty J, Burdge KB, et al. An eclipsing 8.56 minutes orbital
period mass-transferring binary. The Astrophysical Journal. 2026;1000(2).
doi:10.3847/1538-4357/ae4871
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. The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae4871
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.” The Astrophysical Journal. IOP
Publishing, 2026. https://doi.org/10.3847/1538-4357/ae4871.
ieee: E. T. Chickles et al., “An eclipsing 8.56 minutes orbital period mass-transferring
binary,” The Astrophysical Journal, 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.
mla: Chickles, Emma T., et al. “An Eclipsing 8.56 Minutes Orbital Period Mass-Transferring
Binary.” The Astrophysical Journal, vol. 1000, no. 2, 237, IOP Publishing,
2026, doi:10.3847/1538-4357/ae4871.
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).
date_created: 2026-04-12T22:01:47Z
date_published: 2026-04-01T00:00:00Z
date_updated: 2026-05-04T06:37:12Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/1538-4357/ae4871
external_id:
arxiv:
- '2601.07925'
file:
- access_level: open_access
checksum: c8f64a78f36224d8e0ea1f324e43e389
content_type: application/pdf
creator: dernst
date_created: 2026-05-04T06:36:00Z
date_updated: 2026-05-04T06:36:00Z
file_id: '21782'
file_name: 2026_AstrophysicalJournal_Chickles.pdf
file_size: 1225916
relation: main_file
success: 1
file_date_updated: 2026-05-04T06:36:00Z
has_accepted_license: '1'
intvolume: ' 1000'
issue: '2'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: An eclipsing 8.56 minutes orbital period mass-transferring binary
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1000
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '21745'
abstract:
- lang: eng
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. '
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)."
article_number: stag505
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Abbigail K.
full_name: Elms, Abbigail K.
last_name: Elms
- first_name: Stefano
full_name: Bagnulo, Stefano
last_name: Bagnulo
- first_name: Pier Emmanuel
full_name: Tremblay, Pier Emmanuel
last_name: Tremblay
- first_name: Tim
full_name: Cunningham, Tim
last_name: Cunningham
- first_name: James
full_name: Munday, James
last_name: Munday
- first_name: John
full_name: Landstreet, John
last_name: Landstreet
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Carl
full_name: Melis, Carl
last_name: Melis
- first_name: Viktoria
full_name: Pinter, Viktoria
last_name: Pinter
- first_name: Alycia
full_name: Weinberger, Alycia
last_name: Weinberger
citation:
ama: Elms AK, Bagnulo S, Tremblay PE, et al. Detection of a weak magnetic field
in the Balmer emission line white dwarf WDJ1653−1001. Monthly Notices of the
Royal Astronomical Society. 2026;548(1). doi:10.1093/mnras/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. Monthly Notices of the Royal Astronomical
Society. Oxford University Press. https://doi.org/10.1093/mnras/stag505
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.” Monthly Notices
of the Royal Astronomical Society. Oxford University Press, 2026. https://doi.org/10.1093/mnras/stag505.
ieee: A. K. Elms et al., “Detection of a weak magnetic field in the Balmer
emission line white dwarf WDJ1653−1001,” Monthly Notices of the Royal Astronomical
Society, vol. 548, no. 1. Oxford University Press, 2026.
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.
mla: Elms, Abbigail K., et al. “Detection of a Weak Magnetic Field in the Balmer
Emission Line White Dwarf WDJ1653−1001.” Monthly Notices of the Royal Astronomical
Society, vol. 548, no. 1, stag505, Oxford University Press, 2026, doi:10.1093/mnras/stag505.
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).
date_created: 2026-04-19T22:07:42Z
date_published: 2026-05-01T00:00:00Z
date_updated: 2026-05-04T12:11:53Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1093/mnras/stag505
external_id:
arxiv:
- '2603.12048'
file:
- access_level: open_access
checksum: 75c48d70d10a9a48875f577e04da80bc
content_type: application/pdf
creator: dernst
date_created: 2026-05-04T12:10:40Z
date_updated: 2026-05-04T12:10:40Z
file_id: '21794'
file_name: 2026_MNRAS_Elms.pdf
file_size: 4991495
relation: main_file
success: 1
file_date_updated: 2026-05-04T12:10:40Z
has_accepted_license: '1'
intvolume: ' 548'
issue: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Detection of a weak magnetic field in the Balmer emission line white dwarf
WDJ1653−1001
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 548
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '21780'
abstract:
- lang: eng
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.
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)."
article_number: stag521
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: S. G.
full_name: Parsons, S. G.
last_name: Parsons
- first_name: A. J.
full_name: Brown, A. J.
last_name: Brown
- first_name: S. L.
full_name: Casewell, S. L.
last_name: Casewell
- first_name: S. P.
full_name: Littlefair, S. P.
last_name: Littlefair
- first_name: Joannes C
full_name: van Roestel, Joannes C
id: 4d122fc8-6083-11f0-87a5-97d68b860333
last_name: van Roestel
- first_name: A.
full_name: Rebassa-Mansergas, A.
last_name: Rebassa-Mansergas
- first_name: R.
full_name: Murillo-Ojeda, R.
last_name: Murillo-Ojeda
- first_name: M.
full_name: Zorotovic, M.
last_name: Zorotovic
- first_name: M. R.
full_name: Schreiber, M. R.
last_name: Schreiber
- first_name: S.
full_name: Bagnulo, S.
last_name: Bagnulo
- first_name: M. A.
full_name: Stroet, M. A.
last_name: Stroet
- first_name: N.
full_name: Castro Segura, N.
last_name: Castro Segura
- first_name: V. S.
full_name: Dhillon, V. S.
last_name: Dhillon
- first_name: M. J.
full_name: Dyer, M. J.
last_name: Dyer
- first_name: J. A.
full_name: Garbutt, J. A.
last_name: Garbutt
- first_name: M. J.
full_name: Green, M. J.
last_name: Green
- first_name: D.
full_name: Jarvis, D.
last_name: Jarvis
- first_name: M. R.
full_name: Kennedy, M. R.
last_name: Kennedy
- first_name: P.
full_name: Kerry, P.
last_name: Kerry
- first_name: J.
full_name: Mccormac, J.
last_name: Mccormac
- first_name: J.
full_name: Munday, J.
last_name: Munday
- first_name: I.
full_name: Pelisoli, I.
last_name: Pelisoli
- first_name: E.
full_name: Pike, E.
last_name: Pike
- first_name: D. I.
full_name: Sahman, D. I.
last_name: Sahman
- first_name: A.
full_name: Yates, A.
last_name: Yates
citation:
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. Monthly Notices of the Royal Astronomical Society. 2026;547(4).
doi:10.1093/mnras/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. Monthly Notices of the Royal Astronomical Society.
Oxford University Press. https://doi.org/10.1093/mnras/stag521'
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.” Monthly Notices of the Royal Astronomical Society.
Oxford University Press, 2026. https://doi.org/10.1093/mnras/stag521.'
ieee: 'S. G. Parsons et al., “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, vol. 547, no. 4. Oxford
University Press, 2026.'
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.'
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.” Monthly
Notices of the Royal Astronomical Society, vol. 547, no. 4, stag521, Oxford
University Press, 2026, doi:10.1093/mnras/stag521.'
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).
date_created: 2026-05-03T22:01:37Z
date_published: 2026-04-01T00:00:00Z
date_updated: 2026-05-07T07:51:58Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1093/mnras/stag521
external_id:
arxiv:
- '2603.12888'
file:
- access_level: open_access
checksum: a64094199db4dedb12fc121b7c65fe97
content_type: application/pdf
creator: dernst
date_created: 2026-05-07T07:51:06Z
date_updated: 2026-05-07T07:51:06Z
file_id: '21834'
file_name: 2026_MNRAS_Parsons.pdf
file_size: 5955512
relation: main_file
success: 1
file_date_updated: 2026-05-07T07:51:06Z
has_accepted_license: '1'
intvolume: ' 547'
issue: '4'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'ZTF J021804.16+071152.93: A dead cataclysmic variable and potential solution
to the missing period bouncer cataclysmic variables'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 547
year: '2026'
...
---
OA_place: publisher
OA_type: hybrid
PlanS_conform: '1'
_id: '21842'
abstract:
- lang: eng
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."
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."
article_number: e052
article_processing_charge: Yes (in subscription journal)
article_type: original
author:
- first_name: Jan
full_name: Kára, Jan
last_name: Kára
- first_name: Liliana
full_name: Rivera Sandoval, Liliana
last_name: Rivera Sandoval
- first_name: Wendy
full_name: Mendoza, Wendy
last_name: Mendoza
- first_name: Thomas
full_name: Maccarone, Thomas
last_name: Maccarone
- first_name: Manuel
full_name: Pichardo Marcano, Manuel
last_name: Pichardo Marcano
- first_name: Luis E.
full_name: Salazar Manzano, Luis E.
last_name: Salazar Manzano
- first_name: Ryan J.
full_name: Oelkers, Ryan J.
last_name: Oelkers
- first_name: Joannes C
full_name: van Roestel, Joannes C
id: 4d122fc8-6083-11f0-87a5-97d68b860333
last_name: van Roestel
citation:
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. Publications
of the Astronomical Society of Australia. 2026;43. doi:10.1017/pasa.2026.10184
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.
Publications of the Astronomical Society of Australia. Cambridge University
Press. https://doi.org/10.1017/pasa.2026.10184
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.” Publications of the Astronomical Society of
Australia. Cambridge University Press, 2026. https://doi.org/10.1017/pasa.2026.10184.
ieee: J. Kára et al., “A study of transients from ground-based surveys reveals
new ultra-compact accreting white dwarf binaries,” Publications of the Astronomical
Society of Australia, vol. 43. Cambridge University Press, 2026.
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.
mla: Kára, Jan, et al. “A Study of Transients from Ground-Based Surveys Reveals
New Ultra-Compact Accreting White Dwarf Binaries.” Publications of the Astronomical
Society of Australia, vol. 43, e052, Cambridge University Press, 2026, doi:10.1017/pasa.2026.10184.
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).
date_created: 2026-05-07T08:55:00Z
date_published: 2026-03-27T00:00:00Z
date_updated: 2026-05-12T06:57:40Z
day: '27'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1017/pasa.2026.10184
file:
- access_level: open_access
checksum: f8f3cd3765948e8b276176c71c9d4e02
content_type: application/pdf
creator: dernst
date_created: 2026-05-12T06:54:10Z
date_updated: 2026-05-12T06:54:10Z
file_id: '21862'
file_name: 2026_PublAstronomicalSocAustralia_Kara.pdf
file_size: 3681016
relation: main_file
success: 1
file_date_updated: 2026-05-12T06:54:10Z
has_accepted_license: '1'
intvolume: ' 43'
language:
- iso: eng
month: '03'
oa: 1
oa_version: Published Version
publication: Publications of the Astronomical Society of Australia
publication_identifier:
eissn:
- 1448-6083
issn:
- 1323-3580
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: A study of transients from ground-based surveys reveals new ultra-compact accreting
white dwarf binaries
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 43
year: '2026'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21897'
abstract:
- lang: eng
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.
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)."
article_number: stag673
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Matthew J
full_name: Green, Matthew J
last_name: Green
- first_name: Thomas R
full_name: Marsh, Thomas R
last_name: Marsh
- first_name: Joannes C
full_name: van Roestel, Joannes C
id: 4d122fc8-6083-11f0-87a5-97d68b860333
last_name: van Roestel
- first_name: Tin Long Sunny
full_name: Wong, Tin Long Sunny
last_name: Wong
- first_name: Diogo
full_name: Belloni, Diogo
last_name: Belloni
- 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
- first_name: Chris M
full_name: Copperwheat, Chris M
last_name: Copperwheat
- first_name: Anurak
full_name: Chakpor, Anurak
last_name: Chakpor
- first_name: V S
full_name: Dhillon, V S
last_name: Dhillon
- first_name: Noel Castro
full_name: Segura, Noel Castro
last_name: Segura
- first_name: Martin J
full_name: Dyer, Martin J
last_name: Dyer
- first_name: James
full_name: Garbutt, James
last_name: Garbutt
- first_name: Dan
full_name: Jarvis, Dan
last_name: Jarvis
- first_name: Vasu
full_name: Kengkriangkrai, 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
- first_name: S P
full_name: Littlefair, S P
last_name: Littlefair
- first_name: James
full_name: McCormac, James
last_name: McCormac
- first_name: James
full_name: Munday, James
last_name: Munday
- first_name: Steven G
full_name: Parsons, Steven G
last_name: Parsons
- first_name: Eleanor
full_name: Pike, Eleanor
last_name: Pike
- first_name: Ingrid
full_name: Pelisoli, Ingrid
last_name: Pelisoli
- first_name: Pablo
full_name: Rodríguez-Gil, Pablo
last_name: Rodríguez-Gil
- first_name: David I
full_name: Sahman, David I
last_name: Sahman
- first_name: Amalie
full_name: Yates, Amalie
last_name: Yates
citation:
ama: Green MJ, Marsh TR, van Roestel JC, et al. No period change in two long-period
AM CVn binaries. Monthly Notices of the Royal Astronomical Society. 2026;548(3).
doi:10.1093/mnras/stag673
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.
Monthly Notices of the Royal Astronomical Society. Oxford University Press.
https://doi.org/10.1093/mnras/stag673
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.” Monthly Notices of the Royal Astronomical
Society. Oxford University Press, 2026. https://doi.org/10.1093/mnras/stag673.
ieee: M. J. Green et al., “No period change in two long-period AM CVn binaries,”
Monthly Notices of the Royal Astronomical Society, vol. 548, no. 3. Oxford
University Press, 2026.
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.
mla: Green, Matthew J., et al. “No Period Change in Two Long-Period AM CVn Binaries.”
Monthly Notices of the Royal Astronomical Society, vol. 548, no. 3, stag673,
Oxford University Press, 2026, doi:10.1093/mnras/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).
date_created: 2026-05-20T14:34:03Z
date_published: 2026-04-09T00:00:00Z
date_updated: 2026-05-21T06:41:41Z
day: '09'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1093/mnras/stag673
external_id:
arxiv:
- '2604.06460'
file:
- access_level: open_access
checksum: 2c4463926c5cb84ce555ef2005b52ddd
content_type: application/pdf
creator: dernst
date_created: 2026-05-21T06:37:42Z
date_updated: 2026-05-21T06:37:42Z
file_id: '21903'
file_name: 2026_MNRAS_Green.pdf
file_size: 3960296
relation: main_file
success: 1
file_date_updated: 2026-05-21T06:37:42Z
has_accepted_license: '1'
intvolume: ' 548'
issue: '3'
keyword:
- 'binaries: close – stars'
- dwarf novae – novae
- cataclysmic variables – white dwarfs
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: No period change in two long-period AM CVn binaries
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 548
year: '2026'
...
---
OA_place: publisher
OA_type: gold
_id: '19840'
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."
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)."
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Tim
full_name: Cunningham, Tim
last_name: Cunningham
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Gracjan
full_name: Sienkiewicz, Gracjan
last_name: Sienkiewicz
- first_name: Peter J.
full_name: Wheatley, Peter J.
last_name: Wheatley
- first_name: Boris T.
full_name: Gänsicke, Boris T.
last_name: Gänsicke
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Riccardo
full_name: Arcodia, Riccardo
last_name: Arcodia
- first_name: David
full_name: Charbonneau, David
last_name: Charbonneau
- first_name: Liam
full_name: Connor, Liam
last_name: Connor
- first_name: Kishalay
full_name: De, Kishalay
last_name: De
- first_name: Pasi
full_name: Hakala, Pasi
last_name: Hakala
- first_name: Scott J.
full_name: Kenyon, Scott J.
last_name: Kenyon
- first_name: Sumit Kumar
full_name: Maheshwari, Sumit Kumar
last_name: Maheshwari
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Jan
full_name: Van Roestel, Jan
last_name: Van Roestel
- first_name: Pier Emmanuel
full_name: Tremblay, Pier Emmanuel
last_name: Tremblay
citation:
ama: Cunningham T, Caiazzo I, Sienkiewicz G, et al. Discovery of two new polars
evolved past the period bounce. Monthly Notices of the Royal Astronomical Society.
2025;540(1):633-649. doi:10.1093/mnras/staf561
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. Monthly Notices of the Royal Astronomical Society.
Oxford University Press. https://doi.org/10.1093/mnras/staf561
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.” Monthly Notices of the Royal Astronomical
Society. Oxford University Press, 2025. https://doi.org/10.1093/mnras/staf561.
ieee: T. Cunningham et al., “Discovery of two new polars evolved past the
period bounce,” Monthly Notices of the Royal Astronomical Society, vol.
540, no. 1. Oxford University Press, pp. 633–649, 2025.
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.” Monthly Notices of the Royal Astronomical Society, vol. 540, no.
1, Oxford University Press, 2025, pp. 633–49, doi:10.1093/mnras/staf561.
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.
date_created: 2025-06-15T22:01:29Z
date_published: 2025-06-01T00:00:00Z
date_updated: 2025-09-30T12:50:33Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1093/mnras/staf561
external_id:
arxiv:
- '2503.12675'
isi:
- '001493143700001'
file:
- access_level: open_access
checksum: 5e675d3696c222e919d6916bad194b01
content_type: application/pdf
creator: dernst
date_created: 2025-06-23T07:28:36Z
date_updated: 2025-06-23T07:28:36Z
file_id: '19864'
file_name: 2025_MonthlyNoticesRAS_Cunningham.pdf
file_size: 3212636
relation: main_file
success: 1
file_date_updated: 2025-06-23T07:28:36Z
has_accepted_license: '1'
intvolume: ' 540'
isi: 1
issue: '1'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: 633-649
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Discovery of two new polars evolved past the period bounce
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 540
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '19964'
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⊙.
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)."
article_number: '47'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Sihao
full_name: Cheng, Sihao
last_name: Cheng
- first_name: Kevin C.
full_name: Schlaufman, Kevin C.
last_name: Schlaufman
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
citation:
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. The Astronomical Journal. 2025;170(1). doi:10.3847/1538-3881/addd21
apa: Cheng, S., Schlaufman, K. C., & 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.
IOP Publishing. https://doi.org/10.3847/1538-3881/addd21
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.” The Astronomical Journal.
IOP Publishing, 2025. https://doi.org/10.3847/1538-3881/addd21.
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,” The Astronomical Journal, vol. 170,
no. 1. IOP Publishing, 2025.
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.
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.” The Astronomical Journal, vol. 170, no. 1, 47, IOP Publishing,
2025, doi:10.3847/1538-3881/addd21.
short: S. Cheng, K.C. Schlaufman, I. Caiazzo, The Astronomical Journal 170 (2025).
date_created: 2025-07-06T22:01:22Z
date_published: 2025-07-01T00:00:00Z
date_updated: 2026-02-19T09:31:41Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/1538-3881/addd21
external_id:
arxiv:
- '2408.03985'
isi:
- '001514518100001'
file:
- access_level: open_access
checksum: 144b0e46aa3dff0cdf8c6ee7d4fe2fe4
content_type: application/pdf
creator: dernst
date_created: 2025-07-08T06:40:54Z
date_updated: 2025-07-08T06:40:54Z
file_id: '19975'
file_name: 2025_AstronomicalJour_Cheng.pdf
file_size: 931173
relation: main_file
success: 1
file_date_updated: 2025-07-08T06:40:54Z
has_accepted_license: '1'
intvolume: ' 170'
isi: 1
issue: '1'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
publication: The Astronomical Journal
publication_identifier:
eissn:
- 1538-3881
issn:
- 0004-6256
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
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
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 170
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '20586'
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.
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)."
article_number: '167'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Joseph A.
full_name: Guidry, Joseph A.
last_name: Guidry
- first_name: Zachary P.
full_name: Vanderbosch, Zachary P.
last_name: Vanderbosch
- first_name: J. J.
full_name: Hermes, J. J.
last_name: Hermes
- first_name: Dimitri
full_name: Veras, Dimitri
last_name: Veras
- first_name: Mark A.
full_name: Hollands, Mark A.
last_name: Hollands
- first_name: Soumyadeep
full_name: Bhattacharjee, Soumyadeep
last_name: Bhattacharjee
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Malia L.
full_name: Kao, Malia L.
last_name: Kao
- first_name: Lou Baya
full_name: Ould Rouis, Lou Baya
last_name: Ould Rouis
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Jan
full_name: Van Roestel, Jan
last_name: Van Roestel
citation:
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. The
Astrophysical Journal. 2025;992(2). doi:10.3847/1538-4357/adfecb
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. The
Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/adfecb
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.” The Astrophysical Journal. IOP Publishing, 2025. https://doi.org/10.3847/1538-4357/adfecb.
ieee: J. A. Guidry et al., “Transiting planetary debris near the Roche limit
of a white dwarf on a 4.97 hr orbit—and its vanishing,” The Astrophysical Journal,
vol. 992, no. 2. IOP Publishing, 2025.
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.
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.” The Astrophysical Journal,
vol. 992, no. 2, 167, IOP Publishing, 2025, doi:10.3847/1538-4357/adfecb.
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).
date_created: 2025-11-02T23:01:33Z
date_published: 2025-10-20T00:00:00Z
date_updated: 2026-02-16T12:43:29Z
day: '20'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/1538-4357/adfecb
external_id:
arxiv:
- '2508.18348'
isi:
- '001592080300001'
file:
- access_level: open_access
checksum: 24892d1b5bfa1867eb0a353f10c31b82
content_type: application/pdf
creator: dernst
date_created: 2025-11-04T12:33:51Z
date_updated: 2025-11-04T12:33:51Z
file_id: '20601'
file_name: 2025_AstrophysicalJour_Guidry.pdf
file_size: 5323398
relation: main_file
success: 1
file_date_updated: 2025-11-04T12:33:51Z
has_accepted_license: '1'
intvolume: ' 992'
isi: 1
issue: '2'
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
eissn:
- 1538-4357
issn:
- 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Transiting planetary debris near the Roche limit of a white dwarf on a 4.97
hr orbit—and its vanishing
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 992
year: '2025'
...
---
OA_place: publisher
OA_type: hybrid
PlanS_conform: '1'
_id: '20588'
abstract:
- lang: eng
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.'
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."
article_number: '104206'
article_processing_charge: Yes (in subscription journal)
article_type: original
arxiv: 1
author:
- first_name: Soumyadeep
full_name: Bhattacharjee, Soumyadeep
last_name: Bhattacharjee
- first_name: Nicole
full_name: Reindl, Nicole
last_name: Reindl
- first_name: Howard E.
full_name: Bond, Howard E.
last_name: Bond
- first_name: Klaus
full_name: Werner, Klaus
last_name: Werner
- first_name: Gregory R.
full_name: Zeimann, Gregory R.
last_name: Zeimann
- first_name: David
full_name: Jones, David
last_name: Jones
- 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
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Jan
full_name: Van Roestel, Jan
last_name: Van Roestel
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Thomas A.
full_name: Prince, Thomas A.
last_name: Prince
- first_name: Ben
full_name: Rusholme, Ben
last_name: Rusholme
- first_name: Russ R.
full_name: Laher, Russ R.
last_name: Laher
- first_name: Roger
full_name: Smith, Roger
last_name: Smith
citation:
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. Publications of the
Astronomical Society of the Pacific. 2025;137(10). doi:10.1088/1538-3873/ae051e
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. Publications of the Astronomical Society
of the Pacific. IOP Publishing. https://doi.org/10.1088/1538-3873/ae051e
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.” Publications
of the Astronomical Society of the Pacific. IOP Publishing, 2025. https://doi.org/10.1088/1538-3873/ae051e.
ieee: S. Bhattacharjee 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,” Publications of the Astronomical
Society of the Pacific, 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.
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.” Publications of the Astronomical
Society of the Pacific, vol. 137, no. 10, 104206, IOP Publishing, 2025, doi:10.1088/1538-3873/ae051e.
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).
date_created: 2025-11-02T23:01:34Z
date_published: 2025-10-01T00:00:00Z
date_updated: 2025-12-01T15:13:50Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1088/1538-3873/ae051e
external_id:
arxiv:
- '2502.18651'
isi:
- '001595690000001'
file:
- access_level: open_access
checksum: cc7d00c349d48458accb0d3df67e4879
content_type: application/pdf
creator: dernst
date_created: 2025-11-04T08:26:39Z
date_updated: 2025-11-04T08:26:39Z
file_id: '20599'
file_name: 2025_PASP_BhattacharjeeS.pdf
file_size: 12677603
relation: main_file
success: 1
file_date_updated: 2025-11-04T08:26:39Z
has_accepted_license: '1'
intvolume: ' 137'
isi: 1
issue: '10'
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
publication: Publications of the Astronomical Society of the Pacific
publication_identifier:
issn:
- 1538-3873
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
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
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 137
year: '2025'
...
---
OA_place: publisher
OA_type: hybrid
_id: '18851'
abstract:
- lang: eng
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.'
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)."
article_number: '014201'
article_processing_charge: No
article_type: original
arxiv: 1
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
- first_name: Valery
full_name: Suleimanov, Valery
last_name: Suleimanov
- first_name: Anna F.
full_name: Pala, Anna F.
last_name: Pala
- first_name: Shrinivas R.
full_name: Kulkarni, Shrinivas R.
last_name: Kulkarni
- first_name: Boris
full_name: Gaensicke, Boris
last_name: Gaensicke
- first_name: Kaya
full_name: Mori, Kaya
last_name: Mori
- first_name: R. Michael
full_name: Rich, R. Michael
last_name: Rich
- first_name: Arnab
full_name: Sarkar, Arnab
last_name: Sarkar
- first_name: Tong
full_name: Bao, Tong
last_name: Bao
- first_name: Raimundo Lopes
full_name: De Oliveira, Raimundo Lopes
last_name: De Oliveira
- first_name: Gavin
full_name: Ramsay, Gavin
last_name: Ramsay
- first_name: Paula
full_name: Szkody, Paula
last_name: Szkody
- first_name: Matthew
full_name: Graham, Matthew
last_name: Graham
- first_name: Thomas A.
full_name: Prince, Thomas A.
last_name: Prince
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Zachary P.
full_name: Vanderbosch, Zachary P.
last_name: Vanderbosch
- first_name: Jan Van
full_name: Roestel, Jan Van
last_name: Roestel
- first_name: Kaustav K.
full_name: Das, Kaustav K.
last_name: Das
- first_name: Yu Jing
full_name: Qin, 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
- first_name: Daniel
full_name: Reiley, Daniel
last_name: Reiley
- first_name: Reed
full_name: Riddle, Reed
last_name: Riddle
citation:
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. Publications of the Astronomical Society of the Pacific.
2025;137(1). doi:10.1088/1538-3873/ada185'
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. Publications of the Astronomical Society of the Pacific.
IOP Publishing. https://doi.org/10.1088/1538-3873/ada185'
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.” Publications of the Astronomical Society of
the Pacific. IOP Publishing, 2025. https://doi.org/10.1088/1538-3873/ada185.'
ieee: 'A. C. Rodriguez et al., “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,
vol. 137, no. 1. IOP Publishing, 2025.'
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.'
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.” Publications of the Astronomical Society of the Pacific, vol.
137, no. 1, 014201, IOP Publishing, 2025, doi:10.1088/1538-3873/ada185.'
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).
date_created: 2025-01-19T23:01:51Z
date_published: 2025-01-01T00:00:00Z
date_updated: 2025-02-27T12:46:32Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1088/1538-3873/ada185
external_id:
arxiv:
- '2408.16053'
isi:
- '001393204700001'
file:
- access_level: open_access
checksum: 02a9be04a6704fc272ed5a976e5fa8c5
content_type: application/pdf
creator: dernst
date_created: 2025-01-20T09:52:34Z
date_updated: 2025-01-20T09:52:34Z
file_id: '18860'
file_name: 2025_PASP_Rodriguez.pdf
file_size: 5155631
relation: main_file
success: 1
file_date_updated: 2025-01-20T09:52:34Z
has_accepted_license: '1'
intvolume: ' 137'
isi: 1
issue: '1'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/3.0/
month: '01'
oa: 1
oa_version: Published Version
publication: Publications of the Astronomical Society of the Pacific
publication_identifier:
issn:
- 0004-6280
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Cataclysmic variables and AM CVn binaries in SRG/eROSITA + Gaia: Volume limited
samples, X-ray luminosity functions, and space densities'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/3.0/legalcode
name: Creative Commons Attribution 3.0 Unported (CC BY 3.0)
short: CC BY (3.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 137
year: '2025'
...
---
OA_place: publisher
OA_type: diamond
_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.'
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.'
article_number: A114
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Aakash
full_name: Bhat, Aakash
last_name: Bhat
- first_name: Evan B.
full_name: Bauer, Evan B.
last_name: Bauer
- first_name: Rüdiger
full_name: Pakmor, Rüdiger
last_name: Pakmor
- first_name: Ken J.
full_name: Shen, Ken J.
last_name: Shen
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Abinaya Swaruba
full_name: Rajamuthukumar, Abinaya Swaruba
last_name: Rajamuthukumar
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Wolfgang E.
full_name: Kerzendorf, Wolfgang E.
last_name: Kerzendorf
citation:
ama: Bhat A, Bauer EB, Pakmor R, et al. Supernova shocks cannot explain the inflated
state of hypervelocity runaways from white dwarf binaries. Astronomy &
Astrophysics. 2025;693(1). doi:10.1051/0004-6361/202451371
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. Astronomy &
Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/202451371
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.” Astronomy & Astrophysics. EDP Sciences, 2025. https://doi.org/10.1051/0004-6361/202451371.
ieee: A. Bhat et al., “Supernova shocks cannot explain the inflated state
of hypervelocity runaways from white dwarf binaries,” Astronomy & Astrophysics,
vol. 693, no. 1. EDP Sciences, 2025.
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 & Astrophysics.
693(1), A114.
mla: Bhat, Aakash, et al. “Supernova Shocks Cannot Explain the Inflated State of
Hypervelocity Runaways from White Dwarf Binaries.” Astronomy & Astrophysics,
vol. 693, no. 1, A114, EDP Sciences, 2025, doi:10.1051/0004-6361/202451371.
short: A. Bhat, E.B. Bauer, R. Pakmor, K.J. Shen, I. Caiazzo, A.S. Rajamuthukumar,
K. El-Badry, W.E. Kerzendorf, Astronomy & Astrophysics 693 (2025).
date_created: 2025-01-19T23:01:51Z
date_published: 2025-01-07T00:00:00Z
date_updated: 2026-02-16T12:08:05Z
day: '07'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1051/0004-6361/202451371
external_id:
arxiv:
- '2407.03424'
isi:
- '001406577300001'
file:
- access_level: open_access
checksum: e532b9c8123c29cfb0ee758e6d00453c
content_type: application/pdf
creator: dernst
date_created: 2025-01-20T09:57:00Z
date_updated: 2025-01-20T09:57:00Z
file_id: '18861'
file_name: 2025_AstronomyAstrophysics_Bhat.pdf
file_size: 1692527
relation: main_file
success: 1
file_date_updated: 2025-01-20T09:57:00Z
has_accepted_license: '1'
intvolume: ' 693'
isi: 1
issue: '1'
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: Supernova shocks cannot explain the inflated state of hypervelocity runaways
from white dwarf binaries
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 693
year: '2025'
...
---
OA_place: publisher
OA_type: diamond
_id: '18866'
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.
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.
article_number: A68
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: M.
full_name: Scalco, M.
last_name: Scalco
- first_name: R.
full_name: Gerasimov, R.
last_name: Gerasimov
- first_name: L. R.
full_name: Bedin, L. R.
last_name: Bedin
- first_name: E.
full_name: Vesperini, E.
last_name: Vesperini
- first_name: M.
full_name: Correnti, M.
last_name: Correnti
- first_name: D.
full_name: Nardiello, D.
last_name: Nardiello
- first_name: A.
full_name: Burgasser, A.
last_name: Burgasser
- first_name: H.
full_name: Richer, H.
last_name: Richer
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: J.
full_name: Heyl, J.
last_name: Heyl
- first_name: M.
full_name: Libralato, M.
last_name: Libralato
- first_name: J.
full_name: Anderson, J.
last_name: Anderson
- first_name: M.
full_name: Griggio, M.
last_name: Griggio
citation:
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.
Astronomy & Astrophysics. 2025;694. doi:10.1051/0004-6361/202452907
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. Astronomy &
Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/202452907
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.” Astronomy &
Astrophysics. EDP Sciences, 2025. https://doi.org/10.1051/0004-6361/202452907.
ieee: M. Scalco et al., “JWST photometry and astrometry of 47 Tucanae. Discontinuity
in the stellar sequence at the star--brown dwarf transition,” Astronomy &
Astrophysics, vol. 694. EDP Sciences, 2025.
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 & Astrophysics. 694, A68.
mla: Scalco, M., et al. “JWST Photometry and Astrometry of 47 Tucanae. Discontinuity
in the Stellar Sequence at the Star--Brown Dwarf Transition.” Astronomy &
Astrophysics, vol. 694, A68, EDP Sciences, 2025, doi:10.1051/0004-6361/202452907.
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 & Astrophysics 694 (2025).
date_created: 2025-01-21T15:29:36Z
date_published: 2025-02-04T00:00:00Z
date_updated: 2025-07-10T11:51:28Z
day: '04'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1051/0004-6361/202452907
external_id:
arxiv:
- '2501.04446'
isi:
- '001414753300007'
file:
- access_level: open_access
checksum: db765ce222df60a1e7c19da1968906a8
content_type: application/pdf
creator: dernst
date_created: 2025-04-16T07:13:31Z
date_updated: 2025-04-16T07:13:31Z
file_id: '19569'
file_name: 2025_AstronomyAstrophysics_Scalco.pdf
file_size: 18080704
relation: main_file
success: 1
file_date_updated: 2025-04-16T07:13:31Z
has_accepted_license: '1'
intvolume: ' 694'
isi: 1
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: JWST photometry and astrometry of 47 Tucanae. Discontinuity in the stellar
sequence at the star--brown dwarf transition
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 694
year: '2025'
...
---
OA_place: publisher
_id: '19025'
abstract:
- lang: eng
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.'
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."
article_number: '024201'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Soumyadeep
full_name: Bhattacharjee, 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
- first_name: M. S.
full_name: Tam, M. S.
last_name: Tam
- first_name: Howard E.
full_name: Bond, Howard E.
last_name: Bond
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Nicholas
full_name: Chornay, Nicholas
last_name: Chornay
- first_name: Matthew J.
full_name: Graham, Matthew J.
last_name: Graham
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Gregory R.
full_name: Zeimann, 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
- first_name: Klaus
full_name: Werner, Klaus
last_name: Werner
- first_name: Hector
full_name: Rodriguez, Hector
last_name: Rodriguez
- first_name: Thomas A.
full_name: Prince, Thomas A.
last_name: Prince
- first_name: Russ R.
full_name: Laher, Russ R.
last_name: Laher
- first_name: Tracy X.
full_name: Chen, Tracy X.
last_name: Chen
- first_name: Reed
full_name: Riddle, Reed
last_name: Riddle
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. Publications of the Astronomical
Society of the Pacific. 2025;137(2). doi:10.1088/1538-3873/ada702
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. Publications of the Astronomical Society of
the Pacific. IOP Publishing. https://doi.org/10.1088/1538-3873/ada702
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.” Publications of the Astronomical
Society of the Pacific. IOP Publishing, 2025. https://doi.org/10.1088/1538-3873/ada702.
ieee: S. Bhattacharjee 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,” Publications of the Astronomical Society
of the Pacific, vol. 137, no. 2. IOP Publishing, 2025.
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.
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.” Publications of the Astronomical Society
of the Pacific, vol. 137, no. 2, 024201, IOP Publishing, 2025, doi:10.1088/1538-3873/ada702.
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).
date_created: 2025-02-16T23:02:33Z
date_published: 2025-02-01T00:00:00Z
date_updated: 2025-09-30T10:32:17Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1088/1538-3873/ada702
external_id:
arxiv:
- '2410.03589'
isi:
- '001416903300001'
file:
- access_level: open_access
checksum: 42b942ee1bf32ed225024e168174be92
content_type: application/pdf
creator: dernst
date_created: 2025-02-17T09:13:41Z
date_updated: 2025-02-17T09:13:41Z
file_id: '19034'
file_name: 2025_PASP_Bhattacharjee.pdf
file_size: 3657568
relation: main_file
success: 1
file_date_updated: 2025-02-17T09:13:41Z
has_accepted_license: '1'
intvolume: ' 137'
isi: 1
issue: '2'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
publication: Publications of the Astronomical Society of the Pacific
publication_identifier:
issn:
- 0004-6280
issnl:
- 0004-6280
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
related_material:
link:
- relation: erratum
url: https://doi.org/10.1088/1538-3873/adbcd8
scopus_import: '1'
status: public
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
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/3.0/legalcode
name: Creative Commons Attribution 3.0 Unported (CC BY 3.0)
short: CC BY (3.0)
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 137
year: '2025'
...
---
OA_place: publisher
OA_type: hybrid
_id: '19439'
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."
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."
article_number: '024202'
article_processing_charge: Yes (in subscription journal)
article_type: original
arxiv: 1
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
- first_name: Pasi
full_name: Hakala, Pasi
last_name: Hakala
- first_name: Pablo
full_name: Rodríguez-Gil, Pablo
last_name: Rodríguez-Gil
- first_name: Tong
full_name: Bao, Tong
last_name: Bao
- first_name: Ilkham
full_name: Galiullin, Ilkham
last_name: Galiullin
- first_name: Jacob A.
full_name: Kurlander, Jacob A.
last_name: Kurlander
- first_name: Casey J.
full_name: Law, Casey J.
last_name: Law
- first_name: Ingrid
full_name: Pelisoli, Ingrid
last_name: Pelisoli
- first_name: Matthias R.
full_name: Schreiber, Matthias R.
last_name: Schreiber
- first_name: Kevin
full_name: Burdge, Kevin
last_name: Burdge
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Jan Van
full_name: Roestel, Jan Van
last_name: Roestel
- first_name: Paula
full_name: Szkody, Paula
last_name: Szkody
- first_name: Andrew J.
full_name: Drake, Andrew J.
last_name: Drake
- first_name: David A.H.
full_name: Buckley, David A.H.
last_name: Buckley
- first_name: Stephen B.
full_name: Potter, Stephen B.
last_name: Potter
- first_name: Boris
full_name: Gaensicke, Boris
last_name: Gaensicke
- first_name: Kaya
full_name: Mori, 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
- first_name: Matthew
full_name: Graham, Matthew
last_name: Graham
- first_name: Mansi M.
full_name: Kasliwal, Mansi M.
last_name: Kasliwal
- first_name: Sam
full_name: Rose, Sam
last_name: Rose
- first_name: Yashvi
full_name: Sharma, Yashvi
last_name: Sharma
- first_name: Tomás
full_name: Ahumada, Tomás
last_name: Ahumada
- first_name: Shreya
full_name: Anand, Shreya
last_name: Anand
- first_name: Akke
full_name: Viitanen, Akke
last_name: Viitanen
- first_name: Avery
full_name: Wold, Avery
last_name: Wold
- first_name: Tracy X.
full_name: Chen, Tracy X.
last_name: Chen
- first_name: Reed
full_name: Riddle, Reed
last_name: Riddle
- first_name: Roger
full_name: Smith, Roger
last_name: Smith
citation:
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.
Publications of the Astronomical Society of the Pacific. 2025;137(2). doi:10.1088/1538-3873/adb0f1'
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. Publications of
the Astronomical Society of the Pacific. IOP Publishing. https://doi.org/10.1088/1538-3873/adb0f1'
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.” Publications of the Astronomical Society of the Pacific. IOP
Publishing, 2025. https://doi.org/10.1088/1538-3873/adb0f1.'
ieee: 'A. C. Rodriguez et al., “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, vol. 137, no. 2. IOP Publishing,
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.'
mla: 'Rodriguez, Antonio C., et al. “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, vol. 137, no. 2, 024202, IOP Publishing,
2025, doi:10.1088/1538-3873/adb0f1.'
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).
date_created: 2025-03-23T23:01:26Z
date_published: 2025-02-01T00:00:00Z
date_updated: 2025-09-30T11:15:10Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1088/1538-3873/adb0f1
external_id:
arxiv:
- '2501.01490'
isi:
- '001427877700001'
file:
- access_level: open_access
checksum: 42d5aa504479c3fdf2a10165a9e3319f
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creator: dernst
date_created: 2025-03-25T10:01:24Z
date_updated: 2025-03-25T10:01:24Z
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file_name: 2025_PubAstronomSocPacific_Rodriguez.pdf
file_size: 3291933
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file_date_updated: 2025-03-25T10:01:24Z
has_accepted_license: '1'
intvolume: ' 137'
isi: 1
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language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
publication: Publications of the Astronomical Society of the Pacific
publication_identifier:
issn:
- 0004-6280
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'A link between White Dwarf pulsars and polars: Multiwavelength observations
of the 9.36-minute period variable Gaia22ayj'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 137
year: '2025'
...
---
OA_place: publisher
OA_type: hybrid
PlanS_conform: '1'
_id: '21241'
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.
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."
article_number: '074202'
article_processing_charge: Yes (in subscription journal)
article_type: original
arxiv: 1
author:
- first_name: 'Soumyadeep '
full_name: 'Bhattacharjee, Soumyadeep '
last_name: Bhattacharjee
- first_name: Zachary P.
full_name: Vanderbosch, Zachary P.
last_name: Vanderbosch
- first_name: Mark A.
full_name: Hollands, Mark A.
last_name: Hollands
- first_name: Pier-Emmanuel
full_name: Tremblay, Pier-Emmanuel
last_name: Tremblay
- first_name: Siyi
full_name: Xu, Siyi
last_name: Xu
- first_name: Joseph A.
full_name: Guidry, Joseph A.
last_name: Guidry
- first_name: J.J.
full_name: Hermes, J.J.
last_name: Hermes
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Jan
full_name: van Roestel, Jan
last_name: van Roestel
- first_name: 'Kareem '
full_name: 'El-Badry, Kareem '
last_name: El-Badry
- first_name: Andrew J.
full_name: Drake, Andrew J.
last_name: Drake
- first_name: Benjamin R.
full_name: Roulston, Benjamin R.
last_name: Roulston
- first_name: Reed
full_name: Riddle, Reed
last_name: Riddle
- first_name: Ben
full_name: Rusholme, Ben
last_name: Rusholme
- first_name: Steven L.
full_name: Groom, Steven L.
last_name: Groom
- first_name: Roger
full_name: Smith, Roger
last_name: Smith
- first_name: Odette
full_name: Toloza, Odette
last_name: Toloza
citation:
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. Publications of the Astronomical Society
of the Pacific. 2025;137(7). doi:10.1088/1538-3873/ade0ea'
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. Publications of the Astronomical Society of the Pacific.
IOP Publishing. https://doi.org/10.1088/1538-3873/ade0ea'
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.” Publications
of the Astronomical Society of the Pacific. IOP Publishing, 2025. https://doi.org/10.1088/1538-3873/ade0ea.'
ieee: 'S. Bhattacharjee 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,” Publications of the Astronomical Society of the Pacific,
vol. 137, no. 7. IOP Publishing, 2025.'
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.'
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.” Publications of the Astronomical Society of the Pacific,
vol. 137, no. 7, 074202, IOP Publishing, 2025, doi:10.1088/1538-3873/ade0ea.'
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).
date_created: 2026-02-16T15:10:51Z
date_published: 2025-07-09T00:00:00Z
date_updated: 2026-02-17T11:35:53Z
day: '09'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1088/1538-3873/ade0ea
external_id:
arxiv:
- '2502.05502'
file:
- access_level: open_access
checksum: 237eddc36e3823b3092fab6aa5bc8655
content_type: application/pdf
creator: dernst
date_created: 2026-02-17T11:30:29Z
date_updated: 2026-02-17T11:30:29Z
file_id: '21289'
file_name: 2025_PASP_Bhattacharjee.pdf
file_size: 8900420
relation: main_file
success: 1
file_date_updated: 2026-02-17T11:30:29Z
has_accepted_license: '1'
intvolume: ' 137'
issue: '7'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
publication: Publications of the Astronomical Society of the Pacific
publication_identifier:
issn:
- 1538-3873
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
status: public
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'
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/3.0/legalcode
name: Creative Commons Attribution 3.0 Unported (CC BY 3.0)
short: CC BY (3.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 137
year: '2025'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21317'
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.
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."
article_number: L57
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Ilkham
full_name: Galiullin, Ilkham
last_name: Galiullin
- first_name: Antonio C.
full_name: Rodriguez, Antonio C.
last_name: Rodriguez
- first_name: Kareem
full_name: El-Badry, Kareem
last_name: El-Badry
- first_name: Ilaria
full_name: Caiazzo, Ilaria
id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
last_name: Caiazzo
orcid: 0000-0002-4770-5388
- first_name: Paula
full_name: Szkody, Paula
last_name: Szkody
- first_name: Pranav
full_name: Nagarajan, Pranav
last_name: Nagarajan
- first_name: Samuel
full_name: Whitebook, Samuel
last_name: Whitebook
citation:
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. The Astrophysical Journal Letters. 2025;990(2). doi:10.3847/2041-8213/adff82
apa: Galiullin, I., Rodriguez, A. C., 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. IOP Publishing. https://doi.org/10.3847/2041-8213/adff82
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.” The Astrophysical Journal Letters. IOP Publishing, 2025. https://doi.org/10.3847/2041-8213/adff82.
ieee: I. Galiullin et al., “Optical spectroscopy of the most compact accreting
binary harboring a magnetic White Dwarf and a hydrogen-rich donor,” The Astrophysical
Journal Letters, vol. 990, no. 2. IOP Publishing, 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.
mla: Galiullin, Ilkham, et al. “Optical Spectroscopy of the Most Compact Accreting
Binary Harboring a Magnetic White Dwarf and a Hydrogen-Rich Donor.” The Astrophysical
Journal Letters, vol. 990, no. 2, L57, IOP Publishing, 2025, doi:10.3847/2041-8213/adff82.
short: I. Galiullin, A.C. Rodriguez, K. El-Badry, I. Caiazzo, P. Szkody, P. Nagarajan,
S. Whitebook, The Astrophysical Journal Letters 990 (2025).
date_created: 2026-02-18T10:17:04Z
date_published: 2025-09-08T00:00:00Z
date_updated: 2026-02-19T07:27:01Z
day: '08'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/2041-8213/adff82
external_id:
arxiv:
- '2508.20170'
file:
- access_level: open_access
checksum: f76556d129aa0e9facc85602b0b5b54d
content_type: application/pdf
creator: dernst
date_created: 2026-02-19T07:24:10Z
date_updated: 2026-02-19T07:24:10Z
file_id: '21329'
file_name: 2025_AstrophysicalJournal_Galiullin.pdf
file_size: 3772189
relation: main_file
success: 1
file_date_updated: 2026-02-19T07:24:10Z
has_accepted_license: '1'
intvolume: ' 990'
issue: '2'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal Letters
publication_identifier:
eissn:
- 2041-8213
issn:
- 2041-8205
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Optical spectroscopy of the most compact accreting binary harboring a magnetic
White Dwarf and a hydrogen-rich donor
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 990
year: '2025'
...