相关论文: Amplitude Modulation in the ZZ Ceti Star GD 244

A study of the star KIC5892969 observed by the Kepler satellite is presented. Its three highest amplitude modes present a strong amplitude modulation. The aim of this work is to investigate amplitude variations in this star and their…

About 30.5 days of nearly uninterrupted broadband photometry of the solar-type star Kappa1 Ceti, obtained with the MOST (Microvariability & Oscillations of STars) satellite, shows evidence for two large starspots with different rotation…

We report the detection of nonradial g-mode oscillations in the DA white dwarfs HS1039+4112 (B=15.9) and HE1429-0343 (B=15.8) from time-series photometry made at the Loiano 1.5 m telescope. The two stars were previously selected as probable…

The ZZ Ceti star KUV 02464+3239 was observed over a whole season at the mountain station of Konkoly Observatory. A rigorous frequency analysis revealed 6 certain periods between 619 and 1250 seconds, with no shorter period modes present. We…

The beta Cephei star delta Ceti was considered one of the few monoperiodic variables in the class. Despite (or perhaps because of) its apparently simple oscillation spectrum, it has been challenging and controversial to identify this star's…

In this paper, we report the detection of amplitude modulation in a delta Scuti star HD118660. We found that the p-mode frequency at 24.3837 c/d varies periodically in amplitude with frequency 0.0558 c/d. However, all other modes are stable…

Context. We continued our ground-based observing project with the season-long observations of ZZ Ceti stars at Konkoly Observatory. Our present targets are the newly discovered PM J22299+3024, and the already known LP 119-10 variables. LP…

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…

K2 photometry is suitable for the exploitation of mode variability on short timescales in hot B subdwarf stars, which is important to constrain nonlinear quantities addressed by the stellar theory of high-order perturbation in the future.…

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…

G\,29$-$38 (TIC~422526868) is one of the brightest ($V=13.1$) and closest ($d = 17.51$\,pc) pulsating white dwarfs with a hydrogen-rich atmosphere (DAV/ZZ Ceti class). It was observed by the {\sl TESS} spacecraft in sectors 42 and 56. The…

We carried out a new and sensitive search for long-period variability in the prototype of the Mira class of long-period pulsating variables, o Ceti (Mira A), the closest and brightest Mira variable. We conducted this search using an…

We report the discovery of two new ZZ Ceti pulsators, LP 133-144 and HE 1258+0123, selected on the basis of model atmosphere fits to optical spectroscopic data. The atmospheric parameters for LP 133-144, Teff = 11,800 +/- 200 K and log g =…

We present the observed pulsation spectra of all known non-interacting ZZ Ceti stars (hydrogen atmosphere white dwarf variables; DAVs) and examine changes in their pulsation properties across the instability strip. We confirm the well…

We present a detailed analysis of time-resolved optical spectra of the ZZ Ceti white dwarf, HS 0507+0434B. Using the wavelength dependence of observed mode amplitudes, we deduce the spherical degree, l, of the modes, most of which have l=1.…

We present the analysis of time-resolved spectroscopy of the pulsating sdB star PG1605+072. From our main observing run of 16 nights we have detected velocity variations at 5 frequencies that correspond to those found in photometry. Based…

Aims. We use the Kepler data accumulated on the pulsating DB white dwarf KIC 08626021 to explore in detail the stability of its oscillation modes, searching in particular for evidences of nonlinear behaviors. Methods. We analyse nearly two…

We present the first results of an observational project, which addresses the period changing behaviour of a sample of high-amplitude delta Scuti stars. In this paper we discuss the double-mode nature of V567 Ophiuchi. It was observed on 15…

We present results of a 2014-2018 campaign of radial velocity measurements of $\delta$ Ceti. Combining our determination of pulsation period with historical data we conclude that the most likely explanation of observed changes is the…

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…