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The nature of light variations in magnetic hot stars

Niemczura, E.; Huang, L.; Krtička, J. +6 more

Magnetic stars show several types of light variability which is modulated by the stellar rotation. In chemically peculiar stars, the redistribution of the flux in the surface regions with peculiar chemical composition leads to the light variability with a typical amplitude of the order of hundredths of magnitude. The most efficient processes that …

Multiple, short-lived "stellar prominences" on the O giant ξ Persei: a magnetic star?

Henrichs, H. F.; Sudnik, N.

We present strong evidence for a rotation period of 2.0406 d of the O giant ξ Persei, derived from the N_IV λ1718 wind line in 12 yr of IUE data. We predict that ξ Per has a magnetic dipole field, with superposed variable magnetic prominences. Favorable dates for future magnetic measurements can be predicted. We also analysed time-resolv…

Effective temperatures of magnetic CP stars: semi-fundamental data

Stępień, K.; Lipski, Ł.

A brief discussion of earlier determinations of effective temperatures of chemically peculiar stars is given. It is stressed that the effective temperature is a global parameter, important for stellar structure and evolution studies. It should, however, be used with caution in atmospheric investigations. New determinations of effective temperature…

Bolometric correction of the roAp star αCir

Brandão, I. M.; Cunha, M. S.; Gameiro, J. F.

For the first time, the bolometric correction of α Cir was determined. Two values, both based on an estimation of the total integrated flux, were obtained. For that purpose spectroscopic and photometric data of α Cir available in the literature was used. The values derived were then used to place α Cir in the HR diagram.

Atmospheric parameters and abundances of lambda Bootis stars

Heiter, U.

The results of the abundance analyses of six lambda Bootis stars are presented. For three stars, the impact of individual ODFs and various treatments of convection in the calculations of the model atmospheres are investigated.

The energy distribution of Beta CrB for the specific stellar abundances

Castelli, F.

The comparison of the observed and computed energy distributions of Beta CrB has shown that a model with the specific chemical composition of the star can account for the visual energy distribution, while it is still unable to reproduce ultraviolet observations shortward of 1700 Angstroms. Furthermore, the predicted absorption of strong Fe II and …