Related papers: HD 54272, a classical lambda Bootis star and gamma…
It is still a matter of debate if the group of lambda Bootis stars is homogeneously defined. A widely discussed working hypothesis formulates that two apparent solar abundant stars of an undetected spectroscopic binary system mimic a single…
We present results on the second-faintest pulsating subdwarf B (sdB) star known, RAT J0455+1305, derived from photometric data obtained in 2009. It shows both short and long periods oscillations, theoretically assigned as pressure and…
Pulsating subdwarf B (sdB) stars oscillate in short-period p-modes or long-period g-modes. HS0702+6043 (DW Lyn) is one of a few objects to show characteristics of both types and is hence classified as hybrid pulsator. It is one of our…
(abridged) There is considerable interest in the possible interaction between parent stars and giant planetary companions in 51 Peg-type systems. We demonstrate from MOST satellite photometry and Ca II K line emission that there has been a…
We carried out a multi-colour time-series photometric study of six stars claimed as "hybrid" p and g mode pulsators in the literature. Gamma Peg was confirmed to show short-period oscillations of the Beta Cep type and simultaneous…
Context. There exist few variability studies of stars in the region in the Hertzsprung-Russell diagram between the A and B-star pulsational instability strips. With the aid of the high precision continuous measurements of the CoRoT space…
CoRoT and Kepler missions are now providing high-quality asteroseismic data for a large number of stars. Among intermediate-mass and massive stars, fast rotators are common objects. Taking the rotation effects into account is needed to…
HD 90386 is a rarely studied bright A2V type Delta Scuti star (V = 6.66 mag). It displays short-term light curve variations which are originated due to either a beating phenomenon or a non-periodic variation. In this paper, we presented…
We analysed ASAS-3 photometry of bright early-type stars with the goal of finding new Beta Cephei stars. We were particularly interested in stars that would be good for seismic analysis, i.e., stars that (i) have a large number of excited…
SPB star HD 50230, in fact a hybrid B-type pulsator, has been observed by CoRoT least 137 days. A nearly equidistant period spacing pattern are found among 8 modes which are extracted from the oscillation spectrum with more than 500…
We re-classified 31 variable B stars which were observed more than 50 times in the Geneva photometric system with the P7 photometer attached to the MERCATOR telescope (La Palma) during its first 3 years of scientific observations. HD89688…
Context. Gamma Doradus (hereafter $\gamma$~Dor) stars are gravity-mode pulsators whose periods carry information about the internal structure of the star. These periods are especially sensitive to the internal rotation and chemical mixing,…
Observations of the A5p star KIC 8677585 obtained during the Kepler 10-d commissioning run with 1-min time resolution show that it is a roAp star with several frequencies with periods near 10 min. In addition, a low frequency at 3.142…
Blue large-amplitude pulsators (BLAPs) form a small group of hot objects pulsating in a fundamental radial mode with periods of the order of 30 minutes. Proposed evolutionary scenarios explain them as evolved low-mass stars: either ~0.3…
Stars with spectral types earlier than about F0 on (or close) to the main sequence have long been believed to lack observable surface convection, although evolutionary models of A-type stars do predict very thin surface convective zones. We…
We have observed oscillations in the nearby G2 subgiant star beta Hyi using high-precision velocity observations obtained over more than a week with the HARPS and UCLES spectrographs. The oscillation frequencies show a regular comb…
The large-scale magnetic fields detected at the surface of about 10% of hot stars extend into the stellar interior, where they may alter the structure. Deep inner regions of stars are only observable using asteroseismology. Here, we…
We present the first asteroseismic results for $\delta$ Scuti and $\gamma$ Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilise the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding…
We have carried out a photometric survey of a complete, volume-limited sample of gamma Doradus candidates. The sample was extracted from the Hipparcos catalog and consists of 114 stars with colors and absolute magnitudes within the range of…
Context. The object HD 43587Aa is a G0V star observed during the 145-day LRa03 run of the COnvection, ROtation and planetary Transits space mission (CoRoT), for which complementary High Accuracy Radial velocity Planet Searcher (HARPS)…