منابع مشابه
Structure and evolution of low-mass Population II stars
The focus of the present paper is on the detailed description of the internal structures of low mass, population II stars, to clarify some issues about these stellar models and, mainly, their present reliability for observational comparisons. We then explore 1) the role of the local convective model; 2) the differences between “grey” and “non grey” models, and between models in which the photos...
متن کاملCarbon-rich, extremely metal-poor Population II stars
A significant fraction of very metal-poor stars have unexpectedly high carbon abundances. I recap on their discovery, describe the results of high-resolution spectroscopic studies of their composition, and consider possible origins. It is now clear that at least two, and possibly three different explanations are needed for their general characteristics.
متن کاملCarbon Stars
In this review we rst describe basic information for carbon stars starting with the most recent spectral classi cation system of P.C. Keenan and luminosities derived from data in the Hipparcos Catalogue. For the SRb and Lb variables MK = 6:8 1:2 (21 stars). Only two R stars (non-variables) have measured K magnitudes and showMK = 5:2. The four N stars show MV = +0:76 1:06. Using the Magellanic C...
متن کاملThe APM Survey for Cool Carbon Stars in the Galactic Halo - II The Search for Dwarf Carbon Stars
We present proper motion measurements for carbon stars found during the APM Survey for Cool Carbon Stars in the Galactic Halo ( Totten & Irwin, 1998). Measurements are obtained using a combination of POSSI, POSSII and UKST survey plates supplemented where necessary by CCD frames taken at the Isaac Newton Telescope. We find no significant proper motion for any of the new APM colour-selected carb...
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ژورنال
عنوان ژورنال: Progress of Theoretical Physics
سال: 1968
ISSN: 0033-068X
DOI: 10.1143/ptp.39.1432