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 کاملHypervelocity Stars Ii. the Bound Population
Hypervelocity stars (HVSs) are stars ejected completely out of the Milky Way by three-body interactions with the massive black hole in the Galactic center. We describe 643 new spectroscopic observations from our targeted survey for HVSs. We find a significant (3.5σ) excess of B-type stars with large velocities +275 < vrf < 450 km s −1 and distances d > 10 kpc that are most plausibly explained a...
متن کاملLithium 6104 Å in Population II stars
We have obtained échelle spectroscopy of 14 Population II objects selected from those previously observed by Bonifacio & Molaro (1997). For one object, HD 140283, we obtained exquisite data with the High Dispersion Spectrograph on the Subaru Telescope, with S/N exceeding 1000 per 0.018 Å pixel. Li abundances have been determined by spectral synthesis from both the 6708 Å resonance line and also...
متن کاملTransition From Population III to Population II Stars
The transition from Population III to Population II stars is determined by the presence of a sufficient amount of metals, in particular, oxygen and carbon. The vastly different yields of these relevant metals between different initial stellar mass functions would then cause such a transition to occur at different times. We show that the transition from Pop III to Pop II stars is likely to occur...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 1962
ISSN: 0004-6256
DOI: 10.1086/108816