Proceedings of the International Astronomical Union

Contributed Papers

Properties of Wolf-Rayet Stars

Paul A. Crowthera1

a1 Department of Physics and Astronomy, University of Sheffield, S3 7RH, UK email: Paul.Crowther@sheffield.ac.uk

Abstract

A review of recent progress relating to Wolf-Rayet (WR) stars is presented. Topics include improved Milky Way statistics from near-IR surveys, different flavours of hydrogen-rich and hydrogen-poor WN stars, WR masses from binary orbits, plus spectroscopic analysis of WR stars resulting in stellar temperatures, luminosities, ionizing fluxes, plus wind properties accounting for clumping. Chemical abundances of WN and WC stars are presented, including a discussion of neon abundances in WC and WO stars from Spitzer observations. Empirical evidence supporting metallicity-dependent winds is also presented, including its effect on subtype distributions in different environments. Finally, difficulties in comparisons between evolutionary models and observations are highlighted, plus outstanding issues with predictions from continuous star formation and instantaneous bursts in the Milky Way,

Keywords

  • stars: Wolf-Rayet – stars: fundamental parameters – stars: atmospheres – stars: evolution – stars: abundances – stars: mass loss – stars: winds;
  • outflows