منابع مشابه
Understanding A-type supergiants II. Atmospheric parameters and rotational velocities of Galactic A-type supergiants
We present the second paper of a series whose aim is to perform a global study of Galactic A-supergiants. Very little work has been carried out to determine the stellar parameters of these stars. This is illustrated with a brief review of some previous works. In this paper we analyze the determination of absolute magnitudes, spectral types and atmospheric parameters using the most recent Kurucz...
متن کاملA Search for Late-type Supergiants in the Inner Regions of the Milky Way
We present the results of a narrow-band infrared imaging survey of a narrow strip (12 ′ wide) around the galactic equator between 6 • and 21 • of galactic longitude aimed at detecting field stars with strong CO absorption, mainly late-type giants and supergiants. Our observations include follow-up low resolution spectroscopy (R = 980) of 191 selected candidates in the H and K bands. Most of the...
متن کاملUnderstanding B-type supergiants in the low metallicity
Despite a resurgence of effort over the last decade in the area of massive stars there is still ambiguity over their evolutionary path, contamination of their surface abundances and the behaviour of their stellar winds. Here 10 SMC B-type supergiants are analysed applying a unified model atmosphere code FASTWIND to intermediate resolution spectra from the ESO Multi Mode Instrument (EMMI) on the...
متن کاملOn The Pulsational Stability of Blue Supergiants
The brightest blue supergiants represent the most massive evolved stars known. They are believed to be in the core helium-burning phase of evolution. To discuss the question of their stability, model interiors of core helium-burning stars with hydrogen-burning shells have been constructed and tested for pulsational instability (15-1000 M0). All models are found to be extremely stable against nu...
متن کاملOn the nature of the bi-stability jump in the winds of early-type supergiants
We study the origin of the bi-stability jump in the terminal velocity of the winds of supergiants near spectral type B1. Observations show that here the ratio v∞/vesc drops steeply from about 2.6 at types earlier than B1 to a value of v∞/vesc=1.3 at types later than B2. To this purpose, we have calculated wind models and mass-loss rates for early-type supergiants in a Teff grid covering the ran...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1997
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/285.3.529