منابع مشابه
On the evolutionary status of Be stars
We present a study of the incidence of Be stars in open clusters as a function of the cluster age, using whenever possible ages determined through Strömgren uvby photometry. For the first time in studies of this kind we have considered separately classical and Herbig Be stars. The main results can be summarized as follows: – Clusters associated to emitting nebulosities and undergoing stellar fo...
متن کاملVLTI / VINCI diameter constraints on the evolutionary status of δ Eri , ξ Hya , η Boo
Using VLTI/VINCI angular diameter measurements, we constrain the evolutionary status of three asteroseismic targets: the stars δ Eri, ξ Hya, η Boo. Our predictions of the mean large frequency spacing of these stars are in agreement with published observational estimations. Looking without success for a companion of δ Eri we doubt on its classification as an RS CVn star.
متن کاملOn the evolutionary status of λBootis stars using Hipparcos data
Using the Hipparcos data, absolute magnitudes and thus the evolutionary status for the group of λBootis stars were derived. The origin of this small group of non-magnetic, chemically peculiar stars, still remains a matter of debate. Using new evolutionary tracks, an age determination could be provided to distinguish between the two competing theories the diffusion/mass-loss and the accretion. T...
متن کاملAndersson On the Evolutionary Status of Extremely Hot Helium Stars — are O ( He ) Stars Successors of RCrB Stars ?
95% of all stars end their lives as white dwarfs. About 20% of the hot post-AGB stars are hydrogen deficient. Most of these are the result of a late helium-shell flash, but the evolutionary status of a fraction of about 10–20% of the hottest hydrogen-deficient stars, namely four O(He) stars, is as yet unexplained. They could be the long-searched hot successors of RCrB stars, which have not been...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1995
ISSN: 0252-9211
DOI: 10.1017/s0252921100037271