The Multiplicity and Variability of Luminous Blue Variables
Noel Richardson
Université de Montréal

Luminous Blue Variables (LBVs) are massive stars in a rare, transitionary post-main sequence evolutionary phase. These stars have attained luminosities near the Eddington limit and show variability on timescales from hours to years. I will review the unusual observational and theoretical history of these objects amongst the massive stars. In recent years, a few paradoxes have emerged in the study of these objects. First, the binary frequency seems extremely low when compared to the massive, main-sequence O stars. Secondly, these evolved stars were theoretically expected to be slow rotators, but at least a few of these stars are rapidly rotating at 90% critical velocity. I will review recent findings related to the multiplicity issue and detail the variability of the binary systems. Then, I will review some recent efforts to understand the LBV variability using both ground-based spectroscopy and photometry and space-based photometry from the Canadian MOST satellite.

Date:	Vendredi, 4 octobre 2013
Time:	12:30
Where:	Université Laval
	Pavillon Alexandre-Vachon, local 1661