# HOT HORIZONTAL BRANCH STARS IN ω CENTAURI: CLUES ABOUT THEIR ORIGIN FROM THE CLUSTER COLOR MAGNITUDE DIAGRAM

@article{Cassisi2009HOTHB,
title={HOT HORIZONTAL BRANCH STARS IN $\omega$ CENTAURI: CLUES ABOUT THEIR ORIGIN FROM THE CLUSTER COLOR MAGNITUDE DIAGRAM},
author={Santi Cassisi and Maurizio Salaris and Jay Anderson and Giampaolo Piotto and Adriano Pietrinferni and Antonino P. Milone and Andrea Bellini and Luigi R. Bedin},
journal={The Astrophysical Journal},
year={2009},
volume={702},
pages={1530 - 1535}
}
• Published 21 July 2009
• Physics
• The Astrophysical Journal
We investigate a peculiar feature at the hottest, blue end of the horizontal branch of Galactic globular cluster ω Centauri, using the high-precision and nearly complete catalog that has been constructed from a survey taken with the Advanced Camera for Survey on board the Hubble Space Telescope, that covers the inner 10 × 10 arcmin. It is a densely populated clump of stars with an almost vertical structure in the F435W-(F435W−F625W) plane, that we termed “blue clump.” A comparison with…
• Physics
• 2013
Context. Recent investigations revealed very peculiar properties o f blue horizontal branch (HB) stars in ω Centauri, which show anomalously low surface gravity and mass compared to other clusters
• Physics
• 2012
We have investigated the color–magnitude diagram of ω Centauri and find that the blue main sequence (bMS) can be reproduced only by models that have a helium abundance in the range Y = 0.35–0.40. To
• Physics
• 2010
Context. UV observations of some massive globular clusters have revealed a significant population of stars hotter and fainter than the hot end of the horizontal branch (HB), the so-called blue hook
• Physics
• 2012
We analyze the reddening, surface helium abundance and mass of 115 horizontal branch (HB) and blue hook (BH) stars in OmegaCentauri, spanning the HB from the blue edge of the instability strip to
• Physics, Geology
Nature
• 2015
The presence of helium core masses up to about 0.04 solar masses larger than the core mass resulting from evolution is required to solve the luminosity range problem and is modeled by taking into account the dispersion in rotation rates achieved by the progenitors.
• Physics
• 2013
Multi-band Hubble Space Telescope photometry reveals that the main sequence, sub-giant, and the red-giant branch of the globular cluster NGC 6752 splits into three main components in close analogy
• Physics
• 2014
We present an abundance analysis of 96 horizontal branch (HB) stars in NGC 2808, a globular cluster exhibiting a complex multiple stellar population p attern. These stars are distributed in different
• Physics
• 2013
We have applied our empirical-point-spread-function-based photometric techniques on a large number of calibration-related WFC3/UVIS UV-B exposures of the core of ω Cen, and found a well-defined split
• Physics
• 2015
We use images acquired with the Hubble Space Telescope Wide Field Camera 3 and new models to probe the Horizontal Branch (HB) population of the We use images acquired with the Hubble Space Telescope
• Physics
• 2016
We interpret the stellar population of $\omega$ Centauri by means of a population synthesis analysis, following the most recent observational guidelines for input metallicities, helium and

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