New Candidate EHB Stars in the Open Cluster NGC 6791: Looking Locally Into the UV-Upturn Phenomenon
Journal
Date Issued
2006
Author(s)
Abstract
Relying on U and B imagery at the Italian Telescopio Nazionale Galileo (TNG), we report here the discovery of a sample of 13 new UV-bright post-HB candidate stars in the field of the Galactic open cluster NGC 6791. Owing to its super-solar metal content ([Fe/H] ≳ 0.2 dex) and estimated age (t ≳ 8 Gyr), this cluster represents the nearest and ideal stellar aggregate to match the distinctive properties of the evolved stellar populations possibly ruling the UV-upturn phenomenon in elliptical galaxies and bulges of spirals. Our ongoing spectroscopic follow-up of this unique UV-bright sample will allow us to assess -- once cluster membership of the candidates is properly checked -- the real nature (e.g., sdB, sdO, AGB-manqué or EHB stars) of these hot sources and their link with the ultraviolet excess emerging from low-mass, metal-rich evolutionary environments of external galaxies.
Volume
15
Start page
49
Issn Identifier
1392-0049
Ads BibCode
2006BaltA..15...49B
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
2006BaltA..15...49B.pdf
Size
53.68 KB
Format
Adobe PDF
Checksum (MD5)
388ac10d8468ae89492f3e0321dcc790