EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 396/3 Article
Free access article

Issue A&A
Volume 396, Number 3, December IV 2002
Page(s) L25 - L29
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20021623



A&A 396, L25-L29 (2002)
DOI: 10.1051/0004-6361:20021623

Letter

A hidden population of Wolf-Rayet stars in the massive galactic cluster Westerlund 1

J. S. Clark1 and I. Negueruela2, 3

1  Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, England, UK
2  Observatoire de Strasbourg, 11 rue de l'Université, 67000 Strasbourg, France
3  Dpto. de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain

(Received 2 October 2002 / Accepted 7 November 2002)

Abstract
We report the discovery of a hitherto undetected population of Wolf-Rayet stars in the young galactic open cluster Westerlund 1 . Optical spectroscopy of the cluster identified 11 such objects; provisional classification suggests that 6 are nitrogen rich (WN) and 5 carbon rich (WC). Including the previously identified Blue, Yellow & Red Super- & Hypergiants, Westerlund 1 clearly has a very rich population of massive post-Main Sequence objects. To date, the post-MS population of Westerlund 1 is significantly larger than that of any other galactic young open cluster - with the possible exception of the Arches - implying that it is potentially amongst the most massive young clusters yet identified in the Local Group.


Key words: stars: evolution -- stars: Wolf Rayet -- galaxies: starbursts

Offprint request: J. S. Clark, jsc@star.ucl.ac.uk

SIMBAD Objects



© ESO 2002


What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.