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Henryk Cugier

Publications and source records attributed to Henryk Cugier.

3 recordsLinked to original sources

BRITE view of $σ$ Scorpii, $β$ Cephei-type star studied for over a century

Preliminary results of the analysis of the combined space-based BRITE and SMEI, and ground-based Stroemgren photometry are presented. The BRITE data allowed to find seven p and three g modes in the frequency spectrum of this star; only four p modes were known in this star prior to this study. The first results of seismic modelling are also presented.

astro-ph.SR

Revising the evolutionary stage of HD 163899: the effects of convective overshooting and rotation

We revise the evolutionary status of the B-type supergiant HD\,163899 based on the new determinations of the mass-luminosity ratio, effective temperature and rotational velocity as well as on the interpretation of the oscillation spectrum of the star. The observed value of the nitrogen-to-carbon abundance fixes the value of the rotation rate of the star. Now, more massive models are strongly preferred than those previously considered and it is very likely that the star is still in the main sequence stage. The rotationally induced mixing manifests as the nitrogen overabundance in the atmosphere, which agrees with our analysis of the HARPS spectra. Thus, HD\,163899 belongs probably to a group of evolved nitrogen-rich main-sequence stars.

astro-ph.SR

Determining the evolutionary stage of HD163899 on the basis of its oscillation spectrum

We present the new interpretation of the oscillation spectrum of HD 163899 based on the new determinations of the effective temperature, mass-luminosity ratio and rotational velocity. These new parameters strongly prefer the more massive models than previously considered. Now it is also possible that the star could be in the main sequence stage. Using the oscillation spectrum as a gauge, we intend to establish which stage of evolution corresponds better to HD 163899.

astro-ph.SR