A Lifetime of Influence: Abstracts, Talks, and Posters
 

New Surprises from the MOST Satellite

Tony Moffat
Université de Montréal

The MOST (Microvariability and Oscillations of STars) microsatellite has now obtained typically a month of non-stop, minute-of-time resolution, high-precision, broadband optical photometry since 2003 for each of a significant number of OB and WR stars. Numerous p- and g-modes were clearly detected in several OB stars, including discovery of g-modes for the first time in a blue supergiant. Many O stars are remarkably quiet. Five presumably single WR stars have been observed so far, each interesting in its own way. In particular, the cool WR stars WR123 (WN8) and WR103 (WC9d) both show mostly short-lived, multimode oscillations with most of the Fourier power occurring on a day or longer timescale. WR123 also revealed a fairly stable 10-hour periodicity. All of these oscillations probably arise in the stellar cores. WR111 (WC5) shows no (coherent) oscillations above the detection limit of 0.05 mmag in the 10-minute period range predicted for strange-mode pulsations at a level of ~2 mmag. WR110 (WN5-6 and a stronger-than-average X-ray source) and WR124 (WN8h), both strongly variable with MOST, are currently being analyzed.