Research Note

Further Wolf-Rayet stars in the starburst cluster Westerlund 1

¹ Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante, Apdo. 99, E03080 Alicante, Spain e-mail: ignacio@dfists.ua.es
² Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
³ Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK

Received: 13 January 2005
Accepted: 14 March 2005

Abstract

We present new low and intermediate-resolution spectroscopic observations of the Wolf Rayet (WR) star population in the massive starburst cluster Westerlund 1. Finding charts are presented for five new WRs – four WNL and one WCL – raising the current total of known WRs in the cluster to 19. We also present new spectra and correct identifications for the majority of the 14 WR stars previously known, notably confirming the presence of two WNVL stars. Finally we briefly discuss the massive star population of Westerlund 1 in comparison to other massive young galactic clusters.