Related papers: The extraordinary frequency pattern variation in {…
Multi-periodic pulsation phenomena of ZZ Ceti variable stars are analyzed within the context of a fractal cosmological paradigm that emphasizes discrete self-similarity in nature. A quantitative test comparing relevant stellar and atomic…
Harmonics are quite common in pulsating stars, and they are always considered to mimic the behaviors of their independent parent pulsation modes and not taken as the key information for asteroseismology. Here, we report an SX Phoenicis star…
Recent numerical and theoretical considerations have shown that low-degree acoustic modes in rapidly rotating stars follow an asymptotic formula and recent observations of pulsations in rapidly rotating delta Scuti stars seem to match these…
Classification of over 50000 TESS stars in sectors 1-18 has resulted in the detection of 766 pulsating main sequence B stars as well as over 5000 $\delta$ Scuti, 2300 $\gamma$ Doradus and 114 roAp candidates. It is found that a distinct…
Context. At this time, the list of known magnetic {\delta} Scuti stars is extremely limited, with only a handful of well-studied examples. Aims. We seek to expand this list, by retrieving targets from a variety of sources and demonstrating…
The 76 frequencies determined from Kepler measurements of the A-type star KIC 9700322 can be understood in a rather simple way as the radial fundamental and first overtone radial modes, a nonradial \ell = 2 quintuplet, stellar rotation and…
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…
A fraction of the extreme horizontal branch stars of globular clusters exhibit a periodic light variability that has been attributed to rotational modulation caused by surface spots. These spots are believed to be connected to inhomogeneous…
The region in the HR-diagram where the main sequence intersects the classical instability strip hosts A- and F-type stars exhibiting a rich variety of physical phenomena, such as pulsations on various time scales and chemical peculiarities.…
Effects of rotational mode coupling on photometric parameters of stellar oscillations are studied. At moderate rotation rates, a strong coupling between modes of spherical harmonic degree, $\ell$, differing by 2 and of the same azimuthal…
Hybrid $\delta$ Scuti-$\gamma$ Doradus pulsating stars show acoustic ($p$) oscillation modes typical of $\delta$ Scuti variable stars, and gravity ($g$) pulsation modes characteristic of $\gamma$ Doradus variable stars simultaneously…
We present the results of a three-year photometric study of the $\delta$ Scuti star UV Trianguli. Our data sets consist of 9378 differential measurements in Johnson V together with a few data collected into the Str\"{o}mgren {\em…
The detection of pulsational frequencies in stellar photometry is required as input for asteroseismological modelling. The second short run (SRa02) of the CoRoT mission has provided photometric data of unprecedented quality and…
The Praesepe cluster contains a number of Delta Sct and Gamma Dor pulsators. Asteroseismology of cluster stars is simplified by the common distance, age and stellar abundances. Since asteroseismology requires a large number of known…
We have investigated the effects of uniform rotation and a specific model for differential rotation on the pulsation frequencies of 10 \Msun\ stellar models. Uniform rotation decreases the frequencies for all modes. Differential rotation…
Asteroseismology involves using the resonant frequencies of a star to infer details about its internal structure and evolutionary state. Oscillation frequencies are most useful when accompanied by accurate measurements of the more…
delta Scuti variables are stars which exhibit periodic changes in their luminosity through radial and non-radial pulsations. Internally, these stars have relatively small convective cores, and convective overshoot can significantly affect…
Several Delta Sct stars were photometrically monitored with the satellite CoRoT and observed in high-resolution spectroscopy from ground. We present here the preliminary analysis of the abundance analysis of several potential CoRoT targets.…
By using a non-local and time-dependent convection theory, we have calculated radial and low-degree non-radial oscillations for stellar evolutionary models with $M=1.4$--3.0\,$\mathrm{M}_\odot$. The results of our study predict theoretical…
We used high-quality Kepler photometry and spectroscopic data to investigate the Kepler binary candidate KIC 5988140. Using the spectrum synthesis method, we derived the fundamental parameters Teff, log g, [M/H], and v.sini and the…