English
Related papers

Related papers: Precision asteroseismology of the pulsating white …

200 papers

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

White dwarf stars have been used as flux standards for decades, thanks to their staid simplicity. We have empirically tested their photometric stability by analyzing the light curves of 398 high-probability candidates and spectroscopically…

Solar and Stellar Astrophysics · Physics 2017-04-19 J. J. Hermes , B. T. Gaensicke , Nicola Pietro Gentile Fusillo , R. Raddi , M. A. Hollands , E. Dennihy , J. T. Fuchs , S. Redfield

We present time-series VLT spectroscopy and NTT photometry of the cataclysmic variable SDSS J220553.98+115553.7, which contains a pulsating white dwarf. We determine a spectroscopic orbital period of 82.825 +/- 0.089 min from velocity…

Astrophysics · Physics 2009-11-13 John Southworth , D W Townsley , B T Gaensicke

We present results from a search for short time-scale white dwarf variability using \texttt{gPhoton}, a time-tagged database of \textit{GALEX} photon events and associated software package. We conducted a survey of $320$ white dwarf stars…

The TESS spacecraft observed the asynchronous polar CD Ind at a two-minute cadence almost continuously for 28 days in 2018, covering parts of 5 consecutive cycles of the system's 7.3-day beat period. These observations provide the first…

Solar and Stellar Astrophysics · Physics 2019-09-04 Colin Littlefield , Peter Garnavich , Koji Mukai , Paul A. Mason , Paula Szkody , Mark Kennedy , Gordon Myers , Robert Schwarz

From an examination of ~18,000 Kepler light curves of K- and M-stars we find some 500 which exhibit rotational periods of less than 2 days. Among such stars, approximately 50 show two or more incommensurate periodicities. We discuss the…

Solar and Stellar Astrophysics · Physics 2016-02-05 Katalin Oláh , Saul Rappaport , Matthew Joss

The internal structures of pulsating white dwarfs can be explored only with asteroseismology. Time series photometric observations were made for the pulsating DA white dwarf (ZZ Ceti star) WD~0246+326 during 9 nights in 2014 with a bi-site…

Solar and Stellar Astrophysics · Physics 2017-10-02 Chun Li , Jianning Fu , Lester Fox-Machado , Jie Su , Fangfang Chen

Hydrogen atmosphere pulsating white dwarfs, also known as DAV stars, are the most abundant type of pulsating white dwarfs. High-temperature DAV stars exhibit in general a small number of pulsation modes and stable frequencies. G132-12 is…

Solar and Stellar Astrophysics · Physics 2021-07-08 Wen-Chao Su , Jian-Ning Fu , Jian-Xing Chen , Lester Fox-Machado , Shi-Jie Zhao , Carmen Ayala-Loera , Jiang-Tao Wang , Yang Pan

There have been relatively few published long-duration, uninterrupted light curves of magnetic cataclysmic variable stars in which the accreting white dwarf's rotational frequency is slightly desynchronized from the binary orbital frequency…

We present optical high-speed photometry of three millisecond pulsars with low-mass ($< 0.3 M_{\odot}$) white dwarf companions, bringing the total number of such systems with follow-up time-series photometry to five. We confirm the…

The V777 Her pulsator KIC 8626021 has been observed continuously by the Kepler space telescope for nine months. Two new independent pulsation modes are detected in the extended dataset, which both match the predicted sequence of \ell = 2…

Solar and Stellar Astrophysics · Physics 2013-01-25 Roy H. Østensen

We present high-speed optical photometric observations, spanning ~2 years, of the recently-discovered white dwarf pulsar AR Scorpii. The amplitudes of the orbital, spin and beat modulations appear to be remarkably stable and repeatable over…

High Energy Astrophysical Phenomena · Physics 2018-05-16 Stephen B. Potter , David A. H. Buckley

Context. Thanks to photometric space missions, we have access to more and more information on the properties of white dwarf stars, especially pulsating ones. In the case of pulsators, we have the opportunity to get an insight into their…

Solar and Stellar Astrophysics · Physics 2023-01-11 Zs. Bognár , Á. Sódor , Gy. Mező

We report on K2 Campaign 8 measurements of a huge white light flare on the L1 dwarf SDSSp J005406.55-003101.8 (EPIC 220186653). The source is a typical L1 dwarf at a distance of $\sim50$ pc, probably an old hydrogen-burning star rather than…

Solar and Stellar Astrophysics · Physics 2017-03-29 John E. Gizis , Rishi R. Paudel , Sarah J. Schmidt , Peter K. G. Williams , Adam J. Burgasser

We report the discovery of short-period photometric variability and modulated Zeeman-split hydrogen emission in SDSSJ125230.93-023417.72 (EPIC 228939929), a variable white dwarf star observed at long cadence in \textit{K2} Campaign 10. The…

Solar and Stellar Astrophysics · Physics 2020-05-04 Joshua S. Reding , J. J. Hermes , Z. Vanderbosch , E. Dennihy , B. C. Kaiser , C. B. Mace , B. H. Dunlap , J. C. Clemens

We present the largest sample of flares ever compiled for a single M dwarf, the active M4 star GJ 1243. Over 6100 individual flare events, with energies ranging from $10^{29}$ to $10^{33}$ erg, are found in 11 months of 1-minute cadence…

We summarize our findings on three cool ZZ Ceti type pulsating white dwarfs. We determined eight independent modes in HS 0733+4119, of which seven are new findings. For GD 154, we detected two new eigenmodes, and the recurrence of the…

KIC10001893 is one out of 19 subdwarf-B (sdB) pulsators observed by the Kepler spacecraft in its primary mission. In addition to tens of pulsation frequencies in the g-mode domain, its Fourier spectrum shows three weak peaks at very low…

Earth and Planetary Astrophysics · Physics 2014-11-05 R. Silvotti , S. Charpinet , E. Green , G. Fontaine , J. H. Telting , R. H. Ostensen , V. Van Grootel , A. S. Baran , S. Schuh , L. Fox Machado

We present a method for finding binaries among pulsating stars that were observed by the Kepler Mission. We use entire four-year light curves to accurately measure the frequencies of the strongest pulsation modes, then track the pulsation…

Solar and Stellar Astrophysics · Physics 2015-06-19 Simon J. Murphy , Timothy R. Bedding , Hiromoto Shibahashi , Donald W. Kurtz , Hans Kjeldsen

A number of White Dwarfs (WDs) in cataclysmic binaries have shown brightness variations consistent with non-radial oscillations as observed in isolated WDs. A few objects have been well-characterized with photometric campaigns in the hopes…

Solar and Stellar Astrophysics · Physics 2016-01-12 Dean M. Townsley , Phil Arras , Lars Bildsten