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Related papers: Towards a pure ZZ Ceti instability strip

200 papers

A photometric variability study of a sample of northern field stars, which previously classified as either PMS or Herbig Ae/Be objects, has been undertaken with the purpose of detecting {\delta} Scuti-type pulsations. Determination of…

Solar and Stellar Astrophysics · Physics 2014-09-05 D. Díaz-Fraile , E. Rodríguez , P. J. Amado

A comparison between linear stability analysis and observations of pulsation modes in five delta Scuti stars, belonging to the same cluster, is presented. The study is based on the work by Michel et al. (1999), in which such a comparison…

Astrophysics · Physics 2009-06-23 J. C. Suarez , E. Michel , G. Houdek , F. Perez Hernandez , Y. Lebreton

We present the results of a comparative period search on different time-scales and modelling of the ZZ Ceti (DAV) star GD 154. We determined six frequencies as normal modes and four rotational doublets around the ones having the largest…

Solar and Stellar Astrophysics · Physics 2015-06-15 M. Paparo , Zs. Bognar , E. Plachy , L. Molnar , P. A. Bradley

ZZ Ceti stars exhibit small amplitude photometric pulsations in multiple gravity-modes. We demonstrate that parametric instability, a form of resonant 3-mode coupling, limits overstable modes to amplitudes similar to those observed. In…

Astrophysics · Physics 2009-10-08 Yanqin Wu , Peter Goldreich

There are different classes of pulsating stars in the H-R diagram. While many of those classes are undisputed, some remain a mystery such as the objects historically called "Maia variables". Whereas the presence of such a class was…

Solar and Stellar Astrophysics · Physics 2024-09-13 F. Kahraman Aliçavuş , G. Handler , S. Chowdhury , E. Niemczura , R. Jayaraman , P. De Cat , D. Ozuyar , F. Aliçavuş

The photometric properties of the variable stars located in the lower part of the classical instability strip are discussed. The importance of the determination of some light curve parameters and their connection with the stellar models are…

Astrophysics · Physics 2007-05-23 Ennio Poretti , Federica Musazzi

We analyse public domain time-series photometric observations of 30 known and candidate binary post-AGB stars for measuring pulsation and orbital periods. We derive periodicities for 17 stars for the first time in the literature. Besides…

Astrophysics · Physics 2008-11-26 L. L. Kiss , A. Derekas , Gy. M. Szabo , T. R. Bedding , L. Szabados

The group of lambda Bootis type stars comprises late B- to early F-type, Population I objects which are basically metal weak, in particular the Fe group elements, but with the clear exception of C, N, O and S. The present work is a…

We present new results on instabilities in rapidly and differentially rotating neutron stars. We model the stars in full general relativity and describe the stellar matter adopting a cold realistic equation of state based on the unified SLy…

General Relativity and Quantum Cosmology · Physics 2010-06-01 Giovanni Corvino , Luciano Rezzolla , Sebastiano Bernuzzi , Roberto De Pietri , Bruno Giacomazzo

We present a large bank of chemical profiles and pulsation periods suited for asteroseismological studies of ZZ Ceti (or DAV) variable stars. Our background equilibrium DA white dwarf models are the result of fully evolutionary computations…

Solar and Stellar Astrophysics · Physics 2012-04-30 Alejandra D. Romero , Alejandro H. Córsico , Leandro G. Althaus , Marcelo M. Miller Bertolami

In this paper we discuss four early F-type variable stars whose periods are an order of magnitude slower than known pulsators of comparable luminosity. They cannot be stars undergoing simple radial pulsations. For one or more of these stars…

Astrophysics · Physics 2007-05-23 Kevin Krisciunas

To search for and study the instabilities in the atmospheres of selected post-AGB stars, we have performed a long-term high-resolution spectroscopy (R=60000) with the spectrograph NES of the 6-meter BTA telescope. Low-amplitude pulsations,…

Solar and Stellar Astrophysics · Physics 2025-02-05 Valentina G. Klochkova , Vladimir E. Panchuk , Nonna S. Tavolzhanskaya , Maksim V. Yushkin

Regular intrinsic brightness variations observed in many stars are caused by pulsations. These pulsations provide information on the global and structural parameters of the star. The pulsation periods range from seconds to years, depending…

Pulsational properties of 1.8 M$_{\odot}$ stellar models covering the latest stages of contraction toward the main sequence up to early hydrogen burning phases are investigated by means of linear nonadiabatic analyses. Results confirm that…

Astrophysics · Physics 2009-11-06 Marian Suran , MarieJo Goupil , Annie Baglin , Yveline Lebreton , Claude Catala

Context. We present our findings on 18 formerly known ZZ Ceti stars observed by the TESS space telescope in 120s cadence mode during the survey observation of the southern ecliptic hemisphere. Aims. We focus on the frequency analysis of the…

There is a fairly tight correlation between the pulsation periods and effective temperatures of ZZ Ceti stars (cooler stars have longer periods). This seems to fit the theoretical picture, where driving occurs in the partial ionization…

Astrophysics · Physics 2007-05-23 A. Kim , D. E. Winget , M. H. Montgomery , S. O. Kepler

In our 2013 Astronomical Review article, we discussed the statistics of variability for 633 faint spectral type A-F stars observed by the Kepler spacecraft during Quarters 6-13. We found six stars that showed no variability with amplitude…

Solar and Stellar Astrophysics · Physics 2015-02-03 Joyce A. Guzik , Paul A. Bradley , Jason Jackiewicz , Joanna Molenda-Zakowicz , Katrien Uytterhoeven , Karen Kinemuchi

We have discovered periodic variations in the light curves of two hot DQ stars from the Sloan Digital Sky Survey, SDSS J220029.08-074121.5 and SDSS J234843.30-094245.3. These are the second and third variables detected among the hot DQs and…

Astrophysics · Physics 2009-11-13 B. N. Barlow , B. H. Dunlap , R. Rosen , J. C. Clemens

We investigate the pulsational properties of Pre--Main-Sequence (PMS) stars by means of linear and nonlinear calculations. The equilibrium models were taken from models evolved from the protostellar birthline to the ZAMS for masses in the…

Astrophysics · Physics 2009-10-30 M. Marconi , F. Palla

We report the discovery of the first identified pulsating DA white dwarf in the field of the Kepler mission, WD J1916+3938 (Kepler ID 4552982). This ZZ Ceti star was first identified through ground-based, time-series photometry, and…