相关论文: Super-slowly rotating Ap (ssrAp) stars: New spectr…
The many peculiarities of Ap stars (not only chemical ones, but also magnetic field and slow rotation) may vary during the main-sequence evolution of these stars. We review here briefly the evidences found in the last thirty years for such…
Stars are not perfectly spherically symmetric. They are deformed by rotation and magnetic fields. Until now, the study of stellar shapes has only been possible with optical interferometry for a few of the fastest-rotating nearby stars. We…
The rotational and magnetic properties of many magnetic hot stars are poorly characterized, therefore the MiMeS and BinaMIcS collaborations have collected extensive high-dispersion spectropolarimetric datasets of these targets. We present…
The rapidly oscillating Ap (roAp) stars exhibit pulsational photometric and/or radial velocity variations on time scales of several minutes, which are essential to test current pulsation models as well as our assumptions of atmospheric…
Chemically peculiar A stars (Ap) are extreme examples of the interaction of atomic element diffusion processes with magnetic fields in stellar atmospheres. The rapidly oscillating Ap stars provide a means for studying these processes in 3D…
We present the results of a systematic search of the Transiting Exoplanet Survey Satellite (TESS) 2-min cadence data for new rapidly oscillating Ap (roAp) stars observed during the Cycle 2 phase of its mission. We find seven new roAp stars…
From sector 1--44 {\em TESS} observations, 19 new roAp stars, 103 ostensibly non-peculiar stars with roAp-like frequencies and 617 $\delta$~Scuti stars with independent frequencies typical of roAp stars were found. Examination of all…
Before the launch of the Kepler Space Telescope, most studies of the rapidly oscillating Ap (roAp) stars were conducted with ground-based photometric $B$ observations, supplemented with high-resolution time-resolved spectroscopy and some…
We have carried out a survey of short-period pulsations among a sample of carefully chosen cool Ap stars using time-resolved observations with the UVES spectrometer at the ESO 8-m VLT telescope. Here we report the discovery of pulsations…
We report the results of an observational study aimed at searching for magnetic pulsating hot stars suitable for magneto-asteroseismology. A sample of sixteen chemically peculiar stars was selected and analysed using both high-resolution…
Ap star magnetism is often attributed to fossil magnetic fields which have not changed much since the pre-main-sequence epoch of the stars. Stable magnetic field configurations are known which could persist probably for the entire…
The 60 known rapidly oscillating Ap (roAp) stars are excellent laboratories to test pulsation models in the presence of stellar magnetic fields. Our survey is dedicated to search for new group members in the Northern Hemisphere. We attempt…
Among the main sequence intermediate mass A and B stars, around 5% host large-scale organized magnetic fields. Most of these stars are very slow rotators compared to their non-magnetic counterparts, and show photospheric abundance…
We have discovered a new rapidly oscillating Ap star among the Kepler Mission target stars, KIC 10195926. This star shows two pulsation modes with periods that are amongst the longest known for roAp stars at 17.1 min and 18.1 min,…
Magnetic fields play a key role in the pulsations of rapidly oscillating Ap (roAp) stars since they are a necessary ingredient of all pulsation excitation mechanisms proposed so far. This implies that the proper understanding of the…
The results of long-term surveys of radial velocities of cool Ap and Am stars are presented. There are two samples, one of about 100 Ap stars and the other of 86 Am stars. Both have been observed with the CORAVEL scanner from Observatoire…
Three topics are discussed: 1) Photometric observations of the rapidly oscillating Ap stars have shown that the pulsation amplitude drops dramatically as a function of wavelength from the blue to the red. A theoretical derivation, plus…
Recently, high-precision optical 2~min cadence light curves obtained with \emph{TESS} for targets located in the mission's defined first four sectors have been released. The majority of these high-cadence and high-precision measurements…
We have carried out the first survey of the pulsational line profile variability in rapidly oscillating Ap (roAp) stars. We analysed high signal-to-noise time-series observations of ten sharp-lined roAp stars obtained with the…
High-quality light curves from space missions have opened up a new window on the rotational and pulsational properties of magnetic chemically peculiar (mCP) stars and have fuelled asteroseismic studies. They allow the internal effects of…