Related papers: Equidistant frequency triplets in pulsating stars:…
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…
Hybrid stars of the {\gamma} Doradus and {\delta} Scuti pulsation types have great potential for asteroseismic analysis to explore their interior structure. To achieve this, mode identi- fications of pulsational frequencies observed in the…
Using two years of data from the TESS space telescope, we have investigated the time series of 633 overtone pulsating field RR Lyrae (RRc) stars. The majority of stars (82.8 per cent) contain additional frequencies beyond the main…
We report the discovery of a new group of double-periodic stars in the OGLE Galactic bulge photometry. In 38 stars identified as fundamental mode RR~Lyrae and 4 classified as the first-overtone RR~Lyrae, we detected additional shorter…
We present the results of a systematic search for multiperiodic pulsators among the Galactic Bulge RR Lyrae stars of the OGLE-1 sample. We identify one "canonical" double-mode variable (RRd star) pulsating in two radial modes. In 38 stars…
Space-based photometric telescopes stirred up stellar astrophysics in the last decade, and RR Lyrae stars have not been an exception from that either. The long, quasi-continuous, high-precision data from MOST, CoRoT and Kepler revealed a…
We search for signs of period doubling in CoRoT RR Lyrae stars. The occurrence of this dynamical effect in modulated RR Lyrae stars might help us to gain more information about the mysterious Blazhko effect. The temporal variability of the…
CoRoT ID 105733033 is an excellent example of hybrid pulsators as it shows g- and p-modes with almost similar amplitudes in two clearly distinct frequency domains. Classical Fourier analysis allows the dectection of frequencies with an…
Recent theoretical and observational findings breathed new life into the field of RR Lyrae stars. The ever more precise and complete measurements of the space asteroseismology missions revealed new details, such as the period doubling and…
The results of nonlinear, convective models of RR Lyrae pulsators with metal content Z=0.0001 to 0.006 are discussed and several predicted relations connecting pulsational (period and amplitude of pulsation) and evolutionary parameters…
We analyse the OGLE-IV photometry of the first overtone and double-mode RR Lyrae stars (RRc/RRd) in the two fields towards the Galactic bulge observed with high cadence. In 27 per cent of RRc stars we find additional non-radial mode, with…
Combination frequencies are observed in the Fourier spectra of pulsating DA and DB white dwarfs. They appear at sums and differences of frequencies associated with the stellar gravity-modes. Brickhill (1992) proposed that the combination…
Previous studies of the Period--Luminosity relations (PLRs) of Delta Scuti ($\delta$ Sct) stars have focused on those with a single pulsation mode. However, for $\delta$ Sct stars with many different pulsation modes, classifying a single…
We present results of the multicolour UBVR photometry of the high-amplitude EC14026-type star, Balloon 090100001. The data span over a month and consist of more than a hundred hours of observations. Fourier analysis of these data led us to…
According to a recent ray-based asymptotic theory, the high-frequency p-mode spectrum of rapidly rotating stars is a superposition of frequency subsets associated with dynamically independent regions of the ray-dynamics phase space. At high…
We present a seismic study of $\delta$ Scuti based on a mode identification from multicoulor photometry. The dominant frequency can be associated only with a radial mode and the second frequency is, most probably, a dipole mode. The other…
We present a search for X-ray counterparts to RR Lyrae and Cepheid variables using data from the first eROSITA all-sky survey. We identify seven RR Lyrae and eight Cepheid variables with positional matches to X-ray sources. While most…
Recent observations of rapidly rotating stars have revealed the presence of regular patterns in their pulsation spectra. This has raised the question as to their physical origin, and in particular, whether they can be explained by an…
Extensive photometric multisite campaigns of the Delta Scuti variable FG Vir are presented. For the years 2003 and 2004, 926 hours of photometry at the millimag precision level were obtained. The combinations with earlier campaigns lead to…
A rotating, two dimensional stellar model is evolved to match the approximate conditions of Alpha Oph. Both axisymmetric and nonaxisymmetric oscillation frequencies are computed for 2D rotating models which approximate the properties of…