Related papers: The Everchanging Pulsating White Dwarf GD358

2006 Whole Earth Telescope Observations of GD358: A New Look at the Prototype DBV

We report on the analysis of 436.1 hrs of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated XCOV25. The…

Astrophysics · Physics 2011-02-11 J. L. Provencal , M. H. Montgomery , A. Kanaan , H. L. Shipman , D. Childers , A. Baran , S. O. Kepler , M. Reed , A. Zhou , J. Eggen , T. K. Watson , D. E. Winget , S. E. Thompson , B. Riaz , A. Nitta , S. J. Kleinman , R. Crowe , J. Slivkoff , P. Sherard , N. Purves , P. Binder , R. Knight , S. -L. Kim , Wen-Ping Chen , M. Yang , H. C. Lin , C. C. Lin , C. W. Chen , X. J. Jiang , A. V. Sergeev , D. Mkrtichian , E. Janiashvili , M. Andreev , R. Janulis , M. Siwak , S. Zola , D. Koziel , G. Stachowski , M. Paparo , Zs. Bognar , G. Handler , D. Lorenz , B. Steininger , P. Beck , T. Nagel , D. Kusterer , A. Hoffman , E. Reiff , R. Kowalski , G. Vauclair , S. Charpinet , M. Chevreton , J. E. Solheim , E. Pakstiene , L. Fraga , J. Dalessio

Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with {\it TESS}: III. Asteroseismology of the DBV star GD 358

The collection of high-quality photometric data by space telescopes is revolutionizing the area of white-dwarf asteroseismology. Among the different kinds of pulsating white dwarfs, there are those that have He-rich atmospheres, and they…

Solar and Stellar Astrophysics · Physics 2022-03-14 Alejandro H. Córsico , Murat Uzundag , S. O. Kepler , Roberto Silvotti , Leandro G. Althaus , Detlev Koester , Andrzej S. Baran , Keaton J. Bell , Agnès Bischoff-Kim , J. J. Hermes , Steve D. Kawaler , Judith L. Provencal , Don E. Winget , Michael H. Montgomery , Paul A. Bradley , S. J. Kleinman , Atsuko Nitta

GD358: three decades of observations for the in-depth asteroseismology of a DBV star

We report on the analysis of 34 years of photometric observations of the pulsating helium atmosphere white dwarf GD358. The complete data set includes archival data from 1982-2006, and 1195.2 hours of new observations from 2007- 2016. From…

Solar and Stellar Astrophysics · Physics 2019-01-23 Agnes Bischoff-Kim , J. L. Provencal , P. A. Bradley , M. H. Montgomery , H. L. Shipman , Samuel T. Harrold , B. Howard , W. Strickland , D. Chandler , D. Campbell , A. Arredondo , R. Linn , D. P. Russell , D. Doyle , A. Brickhouse , D. Peters , S. -L. Kim , X. J. Jiang , Y-N. Mao , A. V. Kusakin , A. V. Sergeev , M. Andreev , S. Velichko , R. Janulis , E. Pakstiene , F. Alicavus , N. Horoz , S. Zola , W. Ogloza , D. Koziel-Wierzbowska , T. Kundera , D. Jableka , B. Debski , A. Baran , S. Meingast , T. Nagel , L. Loebling , C. Heinitz , D. Hoyer , Zs. Bognar , B. G. Castanheira

A new look at the pulsating DB white dwarf GD 358:Line-of-sight velocity measurements and constraints on model atmospheres

We report on our findings of the bright, pulsating, helium atmosphere white dwarf GD 358, based on time-resolved optical spectrophotometry. We identify 5 real pulsation modes and at least 6 combination modes at frequencies consistent with…

Astrophysics · Physics 2009-11-07 Rubina Kotak , Marten H. van Kerkwijk , J. C. Clemens , Detlev Koester

Time series photometry of the helium atmosphere pulsating white dwarf EC 04207-474

We present the analysis of 71 hours of high quality time-series CCD photometry of the helium atmosphere pulsating white dwarf (DBV) EC 04207-4748 obtained using the facilities at Mt John University Observatory in New Zealand. The…

Solar and Stellar Astrophysics · Physics 2014-12-19 P. Chote , D. J. Sullivan , M. H. Montgomery , J. L. Provencal

Evidence for Temperature Change and Oblique Pulsation from Light Curve Fits of the Pulsating White Dwarf GD 358

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…

Solar and Stellar Astrophysics · Physics 2015-05-18 M. H. Montgomery , J. L. Provencal , A. Kanaan , Anjum S. Mukadam , S. E. Thompson , J. Dalessio , H. L. Shipman , D. E. Winget , S. O. Kepler , D. Koester

Mode identification of Pulsating White Dwarfs using the HST

We have obtained time-resolved ultraviolet spectroscopy for the pulsating DAV stars G226-29 and G185-32, and for the pulsating DBV star PG1351+489 with the Hubble Space Telescope Faint Object Spectrograph, to compare the ultraviolet to the…

Astrophysics · Physics 2009-10-31 S. O. Kepler , E. L. Robinson , D. Koester , J. C. Clemens , R. E. Nather , X. J. Jiang

Whole Earth Telescope observations of the hot helium atmosphere pulsating white dwarf EC 20058-5234

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)…

Astrophysics · Physics 2008-06-17 WET Collaboration , D. J. Sullivan , T. S. Metcalfe , D. O'Donoghue , D. E. Winget , D. Kilkenny , F. van Wyk , A. Kanaan , S. O. Kepler , A. Nitta , S. D. Kawaler , M. H. Montgomery , R. E. Nather , M. S. O'Brien , A. Bischoff-Kim , M. Wood , X. J. Jiang , E. M. Leibowitz , P. Ibbetson , S. Zola , J. Krzesinski , G. Pajdosz , G. Vauclair , N. Dolez , M. Chevreton

Deciphering the Pulsations of G 29-38 with Optical Time Series Spectroscopy

We present optical time series spectroscopy of the pulsating white dwarf star G29-38 taken at the Very Large Telescope (VLT). By measuring the variations in brightness, Doppler shift, and line shape of each spectrum, we explore the physics…

Astrophysics · Physics 2009-11-13 Susan E. Thompson , M. H. van Kerkwijk , J. C. Clemens

The pulsation modes of the pre-white dwarf PG 1159-035

PG 1159-035, a pre-white dwarf with T_eff=140,000 K, is the prototype of both two classes: the PG1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-035 photometric data obtained with the Whole Earth Telescope…

Astrophysics · Physics 2007-12-18 J. E. S. Costa , S. O. Kepler , D. E. Winget , M. S. O'Brien , S. D. Kawaler , A. F. M. Costa , O. Giovannini , A. Kanaan , A. S. Mukadam , F. Mullally , A. Nitta , J. L. Provençal , H. Shipman , M. A. Wood , T. J. Ahrens , A. Grauer , M. Kilic , P. A. Bradley , K. Sekiguchi , R. Crowe , X. J. Jiang , D. Sullivan , T. Sullivan , R. Rosen , J. C. Clemens , R. Janulis , D. O'Donoghue , W. Ogloza , A. Baran , R. Silvotti , S. Marinoni , G. Vauclair , N. Dolez , M. Chevreton , S. Dreizler , S. Schuh , J. Deetjen , T. Nagel , J. -E. Solheim , J. M. Gonzalez Perez , A. Ulla , Martin Barstow , M. Burleigh , S. Good , T. S. Metcalfe , S. -L. Kim , H. Lee , A. Sergeev , M. C. Akan , Ö. Çakirli , M. Paparo , G. Viraghalmy , B. N. Ashoka , G. Handler , Özlem Hürkal , F. Johannessen , S. J. Kleinman , R. Kalytis , J. Krzesinski , E. Klumpe , J. Larrison , T. Lawrence , E. Meištas , P. Martinez , R. E. Nather , J. -N. Fu , E. Pakštienė , R. Rosen , E. Romero-Colmenero , R. Riddle , S. Seetha , N. M. Silvestri , M. Vučković , B. Warner , S. Zola , L. G. Althaus , A. H. Córsico , M. H. Montgomery

Amplitude and frequency variability of the pulsating DB white dwarf stars KUV 05134+2605 and PG 1654+160 observed with the Whole Earth Telescope

We have acquired new time series photometry of the two pulsating DB white dwarf stars KUV 05134+2605 and PG 1654+160 with the Whole Earth Telescope. Additional single-site photometry is also presented. We use all these data plus all…

Astrophysics · Physics 2009-11-07 G. Handler

A New Timescale for Period Change in the Pulsating DA White Dwarf WD 0111+0018

We report the most rapid rate of period change measured to date for a pulsating DA (hydrogen atmosphere) white dwarf (WD), observed in the 292.9 s mode of WD 0111+0018. The observed period change, faster than 10^{-12} s/s, exceeds by more…

Solar and Stellar Astrophysics · Physics 2015-06-15 J. J. Hermes , M. H. Montgomery , Fergal Mullally , D. E. Winget , A. Bischoff-Kim

Mode identification from time-resolved spectroscopy of the pulsating white dwarf G 29-38

We have used time-resolved spectroscopy to measure the colour dependence of pulsation amplitudes in the DAV white dwarf G 29-38. Model atmospheres predict that mode amplitudes should change with wavelength in a manner that depends on the…

Astrophysics · Physics 2009-10-31 J. C. Clemens , M. H. van Kerkwijk , Y. Wu

White Dwarf Variability with gPhoton: Pulsators

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…

Solar and Stellar Astrophysics · Physics 2017-12-27 Michael A. Tucker , Scott W. Fleming , Ingrid Pelisoli , Alejandra Romero , Keaton J. Bell , S. O. Kepler , Daniel B. Caton , John Debes , Michael H. Montgomery , Susan E. Thompson , Detlev Koester , Chase Million , Bernie Shiao

Wandering near the red edge: photometric observations of three cool ZZ Ceti stars

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…

Solar and Stellar Astrophysics · Physics 2018-10-31 Zs. Bognár , M. Paparó , Á. Sódor , D. I. Jenei , Cs. Kalup , E. Bertone , M. Chavez-Dagostino , M. H. Montgomery , Á. Győrffy , L. Molnár , H. Ollé , P. I. Pápics , E. Plachy , E. Verebélyi

High Resolution Spectroscopy of the Pulsating White Dwarf G29-38

We present the analysis of time-resolved, high resolution spectra of the cool white dwarf pulsator, G29-38. From measuring the Doppler shifts of the H-alpha core, we detect velocity changes as large as 16.5 km/s and conclude that they are…

Astrophysics · Physics 2009-11-07 Susan E. Thompson , J. C. Clemens , M. H. van Kerkwijk , D. Koester

Whole Earth Telescope Observations of the subdwarf B star KPD 1930+2752: A rich, short period pulsator in a close binary

KPD 1930+2752 is a short-period pulsating subdwarf B (sdB) star. It is also an ellipsoidal variable with a known binary period just over two hours. The companion is most likely a white dwarf and the total mass of the system is close to the…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. D. Reed , S. L. Harms , S. Poindexter , A. -Y. Zhou , J. R. Eggen , M. A. Morris , A. C. Quint , S. McDaniel , A. Baran , N. Dolez , S. D. Kawaler , D. W. Kurtz , P. Moskalik , R. Riddle , S. Zola , R. H. Ostensen , J. -E. Solheim , S. O. Kepler , A. F. M. Costa , J. L. Provencal , F. Mullally , D. W. Winget , M. Vuckovic , R. Crowe , D. Terry , R. Avila , B. Berkey , S. Stewart , J. Bodnarik , D. Bolton , P. -M. Binder , K. Sekiguchi , D. J. Sullivan , S. -L. Kim , W. -P. Chen , C. -W. Chen , H. -C. Lin , X. -J. Jian , H. Wu , J. -P. Gou , Z. Liu , E. Leibowitz , Y. Lipkin , C. Akan , O. Cakirli , R. Janulis , R. Pretorius , W. Ogloza , G. Stachowski , M. Paparo , R. Szabo , Z. Csubry , D. Zsuffa , R. Silvotti , S. Marinoni , I. Bruni , G. Vauclair , M. Chevreton , J. M. Matthews , C. Cameron , H. Pablo

PSR J1738+0333: The First Millisecond Pulsar + Pulsating White Dwarf Binary

We report the discovery of the first millisecond pulsar with a pulsating white dwarf companion. Following the recent discoveries of pulsations in extremely low-mass (ELM, <0.3 Msol) white dwarfs (WDs), we targeted ELM WD companions to two…

Solar and Stellar Astrophysics · Physics 2015-06-23 Mukremin Kilic , J. J. Hermes , A. Gianninas , Warren R. Brown

Searching for Planets with White Dwarf Pulsations: Spurious Detections

We present 13 years of pulsation timing measurements of the DBV white dwarf EC 2005-5234. Each of the four O-C diagrams mimic the sinusoidal behavior typically attributed to a planet + WD system. However, the amplitude and phase of the O-C…

Earth and Planetary Astrophysics · Physics 2011-04-05 J. Dalessio , J. L. Provencal , H. S. Shipman

The Pulsating Pre-White Dwarf Star PG 0122+200

We present an analysis of single-site time-series photometry of the pulsating pre-white dwarf PG 0122+200. We show the pulsations are consistent with a pattern of modes equally spaced in period; both the observed period range and spacing…

Astrophysics · Physics 2009-10-28 M. Sean O'Brien , J. Christopher Clemens , Steven D. Kawaler , Benjamin T. Dehner