Published online by Cambridge University Press: 26 May 2016
The recent VIIth Catalogue of Galactic Wolf-Rayet Stars (van der Hucht 2001), lists 227 Population I WR stars, comprising 127 WN, 87 WC, 10 WN/WC and 3 WO stars. Additional discoveries since then bring the census to ≳ 253 WR stars, including ≳ 27 WNL and 13 WCL stars within 50 pc of the Galactic Center. A re-determination of the optical photometric distances and the galactic distribution of WR stars shows in the solar neighbourhood (d < 3 kpc) a projected surface density of 2.7 WR stars per kpc2, a N WC/N WN number ratio of 1.3, and a WR binary frequency of 40%. Compared with other Local Group galaxies, the N WC/N WN number ratio in the solar neighborhood is a factor ~2 above the observed metallicity-dependent trend. This could imply that some 30 galactic WN stars in the d < 3 kpc volume are still hiding. Preliminary results of infrared photometric distance determinations are shown. The galactocentric distance (R WR) distribution per subtype shows RWN and RWC decreasing with later WN and WC subtypes. The observed trend is more indicative of WNE → WCE and WNL → WCL subtype evolution than of WNL → WNE and WCL → WCE subtype evolution.
Full text views reflects PDF downloads, PDFs sent to Google Drive, Dropbox and Kindle and HTML full text views.