Table of Contents
ISRN Astronomy and Astrophysics
Volume 2011, Article ID 632850, 6 pages
http://dx.doi.org/10.5402/2011/632850
Research Article

A New Galactic Wolf-Rayet Star in Centaurus

Astronomy Group, Department of Physics, Universidad de La Serena, Cisternas 1200, La Serena, Chile

Received 6 April 2011; Accepted 16 May 2011

Academic Editor: J. A. L. Aguerri

Copyright Β© 2011 A. Roman-Lopes. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

I communicate the detection of a new Galactic Wolf-Rayet star (WR60a) in Centaurus. The H- and K-band spectra of WR60a show strong carbon near-infrared emission lines, characteristic of Wolf-Rayet stars of the WC5-7 subtype. Adopting mean absolute magnitude MK and mean intrinsic ( 𝐽 - 𝐾 𝑆 ) and ( 𝐻 - 𝐾 𝑆 ) colours, it was found that WR60a suffers a mean visual extinction of 3 . 8 Β± 1 . 3 magnitudes, being located at a probable heliocentric distance of 5 . 2 Β± 0 . 8  Kpc, which for the related Galactic longitude ( l = 3 1 2 ) puts this star probably in the Carina-Sagittarius arm at about 5.9 kpc from the Galactic center. I searched for clusters in the vicinity of WR60a and in principle found no previously known clusters in a search radius region of several tens arcminutes. The detection of a well-isolated WR star induced us to seek for some still unknown cluster, somewhere in the vicinity of WR60a. From inspection of 5.8 μm and 8.0 μm Spitzer/IRAC GLIMPSE images of the region around the new WR star, strong mid-infrared extended emission at about 13.5 arcmin south-west of WR60a was found. The study of the H-KS colour distribution of point sources associated with the extended emission reveals the presence of a new Galactic cluster candidate probably formed by at least 85 stars.