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Related papers: Mode identification of Pulsating White Dwarfs usin…

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We performed time-series photometry of the PG1159-type star HE 1429-1209, which was recently discovered in the ESO SPY survey. We show that the star is a low-amplitude (about 0.05 mag) non-radial g-mode pulsator with a period of 919s. HE…

Astrophysics · Physics 2009-11-10 T. Nagel , K. Werner

Pulsating subdwarf B stars oscillate in short-period $p$-modes or long-period $g$-modes. HS 0702 + 6043 is one of currently three objects known to show characteristics of both types and hence is classified as hybrid pulsator. We briefly…

Astrophysics · Physics 2008-12-31 R. Lutz , S. Schuh , R. Silvotti , R. Kruspe , S. Dreizler

Gamma Doradus are F-type stars pulsating with high order g-modes. Their instability strip (IS) overlaps the red edge of the delta Scuti one. This observation has led to search for objects in this region of the HR diagram showing p and…

Solar and Stellar Astrophysics · Physics 2015-05-14 M. -P. Bouabid , J. Montalban , A. Miglio , M. -A. Dupret , A. Grigahcene , A. Noels

We examine high-cadence space photometry taken by the Transiting Exoplanet Survey Satellite (TESS) of a sample of evolved massive stars (26 Wolf-Rayet stars and 8 Luminous Blue Variables or candidate LBVs). To avoid confusion problems, only…

Solar and Stellar Astrophysics · Physics 2021-02-22 Yael Naze , Gregor Rauw , Eric Gosset

About 766 $\delta$ Scuti stars were observed by LAMOST by June 16, 2017. Stellar atmospheric parameters of 525 variables were determined, while spectral types were obtained for all samples. In the paper, those spectroscopic data are…

Solar and Stellar Astrophysics · Physics 2018-01-31 S. B. Qian , L. J. Li , J. J. He , J. Zhang , L. Y. Zhu , Z. T. Han

Context. Thanks to the high-precision photometry from space missions such as Kepler and TESS, tidal perturbations and tilting of pulsations have been detected in more than a dozen binary systems. However, only two of these were g-mode…

Solar and Stellar Astrophysics · Physics 2023-03-15 T. Van Reeth , C. Johnston , J. Southworth , J. Fuller , D. M. Bowman , L. Poniatowski , J. Van Beeck

We present the discovery of 816 high amplitude infrared variable stars ($\Delta K_{\rm s} >$ 1 mag) in 119 deg$^2$ of the Galactic midplane covered by the Vista Variables in the Via Lactea (VVV) survey. Almost all are new discoveries and…

The magnetic cataclysmic variable DQ Herculis was observed with the Faint Object Spectrograph onboard the Hubble Space Telescope (HST) over four consecutive satellite orbits, including the first observation in the UV of DQ Her through…

Astrophysics · Physics 2009-10-28 Andrew D. Silber , Scott F. Anderson , Bruce Margon , Ronald A. Downes

Knowledge of the geometry of pulsational modes is a prerequisite for seismic modelling of stars. In the case of slowly pulsating B-type (SPB) pulsators, the simple zero-rotation approach so far used for mode identification is usually not…

Solar and Stellar Astrophysics · Physics 2015-06-24 W. Szewczuk , J. Daszyńska-Daszkiewicz

Irradiated brown dwarfs offer a unique opportunity to bridge the gap between stellar and planetary atmospheres. We present high-quality $\mathit{HST}$/WFC3/G141 phase-resolved spectra of the white dwarf + brown dwarf binary GD 1400,…

We present a mode identification based on new high-resolution time-series spectra of the non-radially pulsating Delta Scuti star FG~Vir (HD 106384, V = 6.57, A5V). From 2002 February to June a global Delta Scuti Network (DSN) campaign,…

We study how rotation affects observable amplitudes of high-order g- and mixed r/g-modes and examine prospects for their detection and identification. Our formalism, which is described in some detail, relies on a nonadiabatic generalization…

Astrophysics · Physics 2007-05-23 J. Daszynska-Daszkiewicz , W. A. Dziembowski , A. A. Pamyatnykh

We present the results of the first theoretical non-radial non-adiabatic pulsational study of M dwarf stellar models with masses in the range 0.1 to 0.5M_solar. We find the fundamental radial mode to be unstable due to an \epsilon mechanism…

Solar and Stellar Astrophysics · Physics 2015-05-30 C. Rodríguez-López , J. MacDonald , A. Moya

Hot DA white dwarfs have fully radiative pure hydrogen atmospheres that are the least complicated to model. Pulsationally stable, they are fully characterized by their effective temperature Teff, and surface gravity log g, which can be…

The {\it Microvariability and Oscillations of Stars (MOST)} satellite observed the B supergiant HD 163899 (B2 Ib/II) for 37 days as a guide star and detected 48 frequencies $\la$ 2.8 c d$^{-1}$ with amplitudes of a few milli-magnitudes…

We announce the discovery of the most massive pulsating hydrogen-atmosphere (DA) white dwarf (WD) ever discovered, GD 518. Model atmosphere fits to the optical spectrum of this star show it is a 12,030 +/- 210 K WD with a log(g) = 9.08 +/-…

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…

We study the tidal excitation of gravity modes (g-modes) in compact white dwarf binary systems with periods ranging from minutes to hours. As the orbit of the system decays via gravitational radiation, the orbital frequency increases and…

High Energy Astrophysical Phenomena · Physics 2012-09-21 James Fuller , Dong Lai

[Context.] The hot subdwarf B star HS0702+6043 is known as a large-amplitude, short-period p-mode pulsator of the EC14026 type. Its atmospheric parameters place it at the common boundary between the empirical instability regions of the…

Astrophysics · Physics 2009-11-11 S. Schuh , J. Huber , S. Dreizler , U. Heber , S. J. O'Toole , E. M. Green , G. Fontaine

Context. In 2020, a publication presented the first-light results for 18 known ZZ Ceti stars observed by the TESS space telescope during the first survey observations of the southern ecliptic hemisphere. However, in the meantime, new…

Solar and Stellar Astrophysics · Physics 2023-06-22 Zs. Bognár , Á. Sódor , I. R. Clark , S. D. Kawaler