相关论文: Modeling the Photometric Variability of Alpha$^2$ …
The magnetic chemically peculiar (CP2) stars of the upper main sequence are well-suited for investigating the impact of magnetic fields on the surface layers of stars, which leads to abundance inhomogeneities (spots) resulting in…
Strong organized magnetic fields have been studied in the upper main sequence chemically peculiar stars for more than half a century. However, only recently have observational methods and numerical techniques become sufficiently mature to…
The magnetic Ap or CP2 stars are natural atomic and magnetic laboratories and ideal testing grounds for the evaluation of model atmospheres. CP2 stars exhibiting photometric variability are traditionally referred to as alpha2 Canum…
The (magnetic) chemically peculiar (CP) stars of the upper main sequence are well-suited laboratories for investigating the influence of magnetic fields on the stellar surface because they produce abundance inhomogeneities (spots), which…
Since the discovery of the spectral peculiarities of their prototype alpha2 Canum Venaticorum in 1897, the so-called ACV variables, which are comprised of several groups of chemically peculiar stars of the upper main sequence, have been the…
Magnetic chemically peculiar (mCP) stars exhibit complex atmospheres that allow the investigation of the interplay of atomic diffusion, magnetic fields, and stellar rotation. A non-uniform surface distribution of chemical elements and the…
In this paper, we investigate the photometric variability of magnetic O-type stars. Such stars possess oblique, predominantly dipolar magnetic fields that confine their winds roughly axisymmetrically about the magnetic equator, thus forming…
We present the results of the study of cataclysmic variables (CVs) and AM Canum Venaticorum (AM CVn) stars with our double dynamo (DD) formalism of angular momentum loss (AML) by magnetic braking (MB). We show that (1) our MB model…
We present the first Doppler images of the prototypical active binary star RS CVn, derived from high-resolution spectra observed in 2004, 2016 and 2017, using three different telescopes and observing sites. We apply the least-squares…
We present a study of high-resolution spectra of RS Canum Venaticorum (RS CVn), a prototype of active binary systems. Our data were obtained from 1998 to 2017 using different telescopes. We analyze the chromospheric activity indicators Ca…
The number of known variable stars has increased by several magnitudes over the last decade, and automated classification routines are becoming increasingly important to cope with this development. Here we show that the "upside-down CBH…
The manifestation of surface spots on magnetic chemically peculiar (mCP) stars is most commonly explained by the atomic diffusion theory, which requires a calm stellar atmosphere and only moderate rotation. While very successful and well…
Massive star winds are important contributors to the energy, momentum and chemical enrichment of the interstellar medium. Strong, organized and predominantly dipolar magnetic fields have been firmly detected in a small subset of massive…
The late-B magnetic chemically peculiar star CU Vir is one of the fastest rotators among the intermediate-mass stars with strong fossil magnetic fields. It shows a prominent rotational modulation of the spectral energy distribution and…
AM Canum Venaticorum (AM CVn) stars are ultra-compact binary systems composed of a white dwarf (WD) primary accreting from a H-deficient donor. They are important as potential progenitors of Type Ia supernovae and laboratories for…
The AM Canum Venaticorum (AM CVn) binaries are a rare group of hydrogen-deficient, ultra-short period, mass-transferring white dwarf binaries, and are possible progenitors of type Ia supernovae. We present time-resolved spectroscopy of the…
The AM Canum Venaticorum (AM CVn) binaries are a rare group of ultra-short period, mass-transferring white dwarf binaries, some of which may be Type Ia supernova progenitors. More than a third of the total known population of AM CVn…
Slowly rotating magnetic massive stars develop "dynamical magnetospheres" (DM's), characterized by trapping of stellar wind outflow in closed magnetic loops, shock heating from collision of the upflow from opposite loop footpoints, and…
We present updated magnetic field maps of the chemically peculiar B9p star $\alpha^2$ CVn created using a series of time resolved observations obtained using the high resolution spectropolarimeters ESPaDOnS and Narval. We compare these new…
Magnetic, chemically peculiar stars are known for exhibiting surface abundance inhomogeneities (chemical spots) that lead to photometric and spectroscopic variability with the rotation period. It is commonly assumed that the surface…