相关论文: Super-slowly rotating Ap (ssrAp) stars: New spectr…
The fundamental properties of low-mass stars are not as well understood as those of their more massive counterparts. The best method for constraining these properties, especially masses and radii, is to study eclipsing binary systems, but…
The magnetic chemically peculiar (mCP) stars of the upper main sequence exhibit strong, globally-organised magnetic fields which are inclined to the rotational axis and facilitate the development of surface abundance inhomogeneities…
We present a comprehensive statistical investigation of the evolution of magnetic CP stars, aimed at providing constraints to the theories that deal with the origin of the magnetic field in these stars. We have collected from the literature…
With FORS1 at the VLT we have tried for the first time to measure the magnetic field variation over the pulsation cycle in six roAp stars to begin the study of how the magnetic field and pulsation interact. For the star HD101065, which has…
We present our discovery of pulsational radial-velocity variations in the cool Ap star HD 75445, an object spectroscopically similar to the bright, rapidly-oscillating Ap (roAp) star gamma Equ. Based on high-resolution time-series…
We perform a search for rapidly oscillating Ap stars in the Kepler long-cadence data, where true oscillations above the Nyquist limit of 283.21 {\mu}Hz can be reliably distinguished from aliases as a consequence of the barycentric time…
Observations made using TESS revealed a sample of low mass stars which show a periodic modulation on a period $<0.2$~d. Surprisingly many of these Ultra Fast Rotating (UFR) stars showed no evidence of flare activity which would be expected…
We continue our studies on stellar latitudinal differential rotation. The presented work is a sequel of the work of Reiners et al. who studied the spectral line broadening profile of hundreds of stars of spectral types A through G at high…
We report the detection of short period variations in the stars HD69013 and HD96237. These stars possess large overabundances of rare earth elements and global magnetic fields, thus belong to the class of chemically peculiar Ap stars of the…
Stellar rotation is a complex function of mass, metallicity, and age and can be altered by binarity. To understand the importance of these parameters in main sequence stars, we have assembled a sample of observations that spans a range of…
We consider three samples of O- and B-type stars from the solar neighborhood 0.6--4 kpc for which we have taken the distances, line-of-sight velocities, and proper motions from published sources. The first sample contains 120 massive…
Recent space-based missions have ushered in a new era of observational astronomy, where high-cadence photometric light curves for thousands to millions of stars in the solar neighborhood can be used to test and apply stellar age-dating…
New high-precision measurements of the longitudinal magnetic field of Ap stars suggest the existence of secular intrinsic variations of the global magnetic field in some stars. We argue that such changes are apparent in the Ap star…
Stars with radiative envelopes, specifically the upper main sequence chemically peculiar (Ap) stars, were among the first objects outside our solar system for which surface magnetic fields have been detected. Currently magnetic Ap stars…
The TESS mission delivers time-series photometry for millions of stars across the sky, offering a probe into stellar astrophysics, including rotation, on a population scale. However, light curve systematics related to the satellite's…
This paper reports the discovery of new slowly pulsating B-type stars. Based on the photometric, spectral, and astrometric data of TESS, LAMOST, and Gaia surveys, we have found 286 new slowly pulsating B-type stars (SPB stars) and 21…
We focus on early-B type stars with helium overabundance, for which the presence of a magnetic field has not previously been reported. The measurements were carried out using high-spectral-resolution spectropolarimetric observations…
We present two new rapidly oscillating Ap (roAp) stars, TIC 198781841 and TIC 229960986, discovered in TESS photometric data. The periodogram of TIC 198781841 has a large peak at 166.506 d$^{-1}$ (1.93 mHz), with two nearby peaks at 163.412…
We obtained thirteen spectropolarimetric observations of the strongly magnetic rapidly oscillating Ap star HD154708 over three months with the multi-mode instrument FORS1, installed at the 8-m Kueyen telescope of the VLT. These observations…
M dwarfs are the most abundant stars in the Galaxy and exhibit diverse magnetic behaviours. Understanding their large-scale magnetic fields is essential to study stellar dynamos and assess the impact of magnetic activity on planetary…