منابع مشابه
ON omega CENTAURI AND ITS RRc STARS
Masses, temperatures, and absolute luminosities are proposed for a large sample of RRc stars in the globular cluster w Centauri. Our technique uses three observed quantities: period, relative luminosity, and Fourier phase CP31' interpreting them in the light of linear and hydrodynamic pulsation models. The masses we obtain agree with those of the RRd stars in other clusters, and our derived par...
متن کاملDouble mode RR Lyrae stars in Omega Centauri
Aims. The aim of this work was to search for double mode pulsators among RR Lyr variables of globular cluster ω Cen. Methods. We conducted a systematic frequency analysis of CASE photometry of ω Cen RR Lyr stars. We searched for periodicities using Fourier and ANOVA periodograms, combined with consecutive prewhitening technique. Results. We discovered six double mode pulsators, with the first o...
متن کاملThe Luminosity Function of Omega Centauri
Deep HST–WFPC2 observations of the stellar population in the globular cluster ωCen (NGC5139) have been used to measure the luminosity function of main sequence stars at the low-mass end. Two fields have been investigated, located respectively ∼ 4 . 6 and ∼ 7 away from the cluster center, or near the half-light radius of this cluster (rhl ≃ 4 ′ . 8). The color-magnitude diagrams derived from the...
متن کاملThe Chemical Evolution of Omega Centauri
The globular cluster ωCen is an outstanding object in terms of both its chemical and kinematic properties. Its large mass, spread in element abundances, chemical and kinematical segregations, as well as its peculiar orbit, all suggest that it is the surviving remnant of a larger system. In this contribution we deal with the chemical evolution of ωCen in the framework of a model where it is the ...
متن کاملOmega Centauri: the Population Puzzle Goes Deeper
We present HST observations that show a bifurcation of colors in the middle main sequence of the globular cluster ω Centauri. We see this in three different fields, observed with different cameras and filters. We also present high precision photometry of a central ACS field which shows a number of main-sequence turnoffs and subgiant branches. The double main sequence, the multiple turnoffs and ...
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 Astrophysical Journal
سال: 1990
ISSN: 0004-637X,1538-4357
DOI: 10.1086/169101