相关论文: Magnetism, chemical spots, and stratification in t…

We report a detailed study of the ground state helical magnetic structure in monophosphide FeP by means of ${}^{31}$P NMR spectroscopy. We show that the zero-field NMR spectrum of the polycrystalline sample provides strong evidence of an…

New spectra have been obtained with the ESPaDOnS spectropolarimeter supplemented with unpolarised spectra from the ESO UVES, UVES-FLAMES, and HARPS spectrographs of the very peculiar large-field magnetic Ap star HD 318107, a member of the…

The determination of fundamental parameters of stars is one of the main tasks of astrophysics. For magnetic chemically peculiar stars, this problem is complicated by the anomalous chemical composition of their atmospheres, which requires…

High spectral resolution studies of cool Ap stars reveal conspicuous anomalies of the shape and strength of many absorption lines. This is a signature of large atmospheric chemical gradients produced by the selective radiative levitation…

We report the first detection of the magnetic field in a star of FS CMa type, a subgroup of objects characterized by the B[e] phenomenon. The split of magnetically sensitive lines in IRAS 17449+2320 determines the magnetic field modulus of…

Observations of magnetic fields of stars at the pre-main sequence phase can provide important new insights into the complex physics of the late stages of star formation. This is especially true at intermediate stellar masses, where magnetic…

We investigate the impact of hyperfine splitting on stellar abundance analyses of Mn and Sc, and find that incorrect hfs treatment can lead to spurious abundance trends with metallicity. We estimate corrections to a recent study by Nissen…

We have obtained a UVES spectrum of a slowly rotating strongly magnetic Ap star, HD 144897, that exhibits very large overabundances of rare-earth elements. Here we present a detailed spectral analysis of this object, also taking into…

I review ongoing efforts to understand the incidence of magnetism in intermediate-mass stars that are different from the magnetic Ap stars. This includes the search for magnetic fields in chemically peculiar stars of the Am and HgMn types…

The stars of the middle main sequence have relatively quiescent outer layers, and unusual chemical abundance patterns may develop in their atmospheres. The presence of chemical peculiarities reveal the action of such subsurface phenomena as…

We present a spectropolarimetric analysis of the hot star V352Peg. We have acquired 18 spectropolarimetric observations of the star with ESPaDOnS at the CFHT between 2018 and 2019 and completed our dataset with one archival ESPaDOnS…

Recent work by Mitra et al. (2014) has shown that in strongly stratified forced two-layer turbulence with helicity and corresponding large-scale dynamo action in the lower layer, a magnetic field occurs in the upper layer in the form of…

Magnetic chemically peculiar (mCP) stars are strongly magnetic upper main-sequence stars that exhibit light rotational variability due to an uneven surface distribution of certain peculiar elements, which may appear in phase at certain…

We present the results of mapping the HgMn star AR Aur using the Doppler Imaging technique for several elements and discuss the obtained distributions in the framework of a magnetic field topology.

The advent of space-based photometry provides the opportunity for the first precise characterizations of variability in Mercury-Manganese (HgMn/CP3) stars, which might advance our understanding of their internal structure. We have carried…

We calculated spectral energy distribution of the helium strong chemically peculiar star HD 37776 using adequate model atmospheres. We show that the chemical peculiarity influences the stellar energy distribution. Consequently, spots of…

A majority part of magnetic chemically peculiar (mCP) stars of the upper main sequence exhibits strictly periodic light, magnetic, radio, and spectral variations that can be fully explained by the model of a rigidly rotating main-sequence…

We present a study of the chemical abundances of Solar neighbourhood stars associated to dynamical structures in the Milky Way's (thick) disk. These stars were identified as overdensity in the eccentricity range 0.3< ecc < 0.5 in the…

The number of magnetic stars detected among massive stars is small; nevertheless, the role played by the magnetic field in stellar evolution cannot be disregarded. Links between line profile variability, enhancements/depletions of surface…

Context. Classical chemically peculiar stars exhibit atmospheres that are often structured by the effects of atomic diffusion. As a result of these elemental diffusion and horizontal abundance variations, photospheric temperature varies at…