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We present an asteroseismic analysis of the helium atmosphere white dwarf (a DBV) recently found in the field of view of the Kepler satellite. We analyze the 5-mode pulsation spectrum that was produced based on one month of high cadence…

Solar and Stellar Astrophysics · Physics 2015-05-30 Agnés Bischoff-Kim , Roy H. Østensen

We present the analysis of a total of 177h of high-quality optical time-series photometry of the helium atmosphere pulsating white dwarf (DBV) EC 20058-5234. The bulk of the observations (135h) were obtained during a WET campaign (XCOV15)…

The determination of atmospheric parameters of white dwarf stars (WDs) is crucial for researches on them. Traditional methodology is to fit the model spectra to observed absorption lines and report the parameters with the lowest $\chi ^2$…

Instrumentation and Methods for Astrophysics · Physics 2021-11-29 Yong Yang , Jingkun Zhao , Jiajun Zhang , Xianhao Ye , Gang Zhao

The interpretation of pulsation data for Sun-like stars is currently facing challenges quite similar to those faced by white dwarf modelers ten years ago. The observational requirements for uninterrupted long-term monitoring are beginning…

Astrophysics · Physics 2009-11-10 Travis S. Metcalfe

Convective driving, the mechanism originally proposed by Brickhill (1991, 1983) for pulsating white dwarf stars, has gained general acceptance as the generic linear instability mechanism in DAV and DBV white dwarfs. This physical mechanism…

The {\sl TESS} space mission has recently demonstrated its great potential to discover new pulsating white dwarf and pre-white dwarf stars, and to detect periodicities with high precision in already known white-dwarf pulsators. We report…

(Abridged) We present an exploration of the internal rotation of GD 278, the first pulsating extremely low-mass white dwarf that shows rotational splittings within its periodogram. We assess the theoretical frequency splittings expected for…

Solar and Stellar Astrophysics · Physics 2023-05-24 Leila M. Calcaferro , Alejandro H. Córsico , Leandro G. Althaus , Isaac D. Lopez , J. J. Hermes

The history of stellar seismology suggests that observation and theory often take turns advancing our understanding. The recent tripling of the sample of pulsating white dwarfs generated by the Sloan Digital Sky Survey represents a giant…

Astrophysics · Physics 2009-11-11 Travis S. Metcalfe

DA-type white dwarfs account for 80% of all white dwarfs and represent, for most of them, the ultimate outcome of the typical evolution of low-to-intermediate mass stars. Their internal chemical stratification is strongly marked by passed,…

Solar and Stellar Astrophysics · Physics 2021-07-09 S. Charpinet , N. Giammichele , P. Brassard , G. Fontaine , P. Bergeron , W. Zong , V. Van Grootel , A. S. Baran

It is possible to reliably identify white dwarfs (WDs) without recourse to spectra, instead using photometric and astrometric measurements to distinguish them from Main Sequence stars and quasars. WDs' colours can also be used to infer…

Astrophysics · Physics 2010-02-22 Daniel J. Mortlock , Hiranya V. Peiris , Zeljko Ivezic

In this work, we present a detailed asteroseismological analysis of WFST J053009.62+594557.0, a newly discovered faint pulsating white dwarf by the Wide Field Survey Telescope (WFST) with a Gaia G magnitude of 19.13. Analysis of two nights…

Aims. By analysing the light curves of the ZZ Ceti star WD 1310+583, we aim to determine its pulsational frequencies and to give constraints on the main stellar parameters using the tools of asteroseismology. Methods. We performed the…

Solar and Stellar Astrophysics · Physics 2026-02-25 Zs. Bognár , M. Uzundag , F. C. De Gerónimo , A. H. Córsico , J. Munday , Á. Sódor , S. D. Barber

The white dwarfs are promising laboratories for the study of cosmochronology and stellar evolution. Through observations of the pulsating white dwarfs, we can measure their internal structures and compositions, critical to understanding…

We search for photometric variability in more than 23,000 known and candidate white dwarfs, the largest ultraviolet survey compiled for a single study of white dwarfs. We use gPhoton, a publicly available calibration/reduction pipeline, to…

Solar and Stellar Astrophysics · Physics 2019-05-01 Dominick M. Rowan , Michael A. Tucker , Benjamin J. Shappee , J. J. Hermes

We present the results of the asteroseismological analysis of two rich DAVs, G38-29 and R808, recent targets of the Whole Earth Telescope. 20 periods between 413 s and 1089 s were found in G38-29's pulsation spectrum, while R808 is an even…

Solar and Stellar Astrophysics · Physics 2010-02-09 A. Bischoff-Kim

The helium-atmosphere (DB) white dwarfs are commonly thought to be the descendants of the hotter PG 1159 stars, which initially have uniform He/C/O atmospheres. In this evolutionary scenario, diffusion builds a pure He surface layer which…

Astrophysics · Physics 2010-12-09 Travis S. Metcalfe

We present a new, better-constrained asteroseismic analysis of the helium-atmosphere (DB) white dwarf discovered in the field of view of the original Kepler mission. Observations obtained over the course of two years yield at least seven…

Solar and Stellar Astrophysics · Physics 2014-08-21 Agnes Kim , Roy Ostensen , J. J. Hermes , Judith Provencal

We investigate the global pulsation properties of DBV white dwarf models that include both the double-layered envelope structure expected from time-dependent diffusion calculations, as well as a non-uniform C/O core expected from prior…

Astrophysics · Physics 2009-11-07 T. S. Metcalfe , M. H. Montgomery , S. D. Kawaler

White dwarfs (WDs), as the remnants of low to intermediate-mass stars, provide a unique opportunity to explore the interplay between quantum mechanical degeneracy pressure and gravitational forces under extreme conditions. In this study, we…

General Relativity and Quantum Cosmology · Physics 2025-05-22 Juan M. Z. Pretel , Takol Tangphati , İzzet Sakallı , Ayan Banerjee

Many pulsating low-mass white-dwarf stars have been detected in the last years in the field of our Galaxy. Given that some of them exhibit multiperiodic variation of brightness, it is possible to probe their interiors through…

Solar and Stellar Astrophysics · Physics 2017-11-08 Leila M. Calcaferro , Alejandro H. Córsico , Leandro G. Althaus