Nils Turner, (Georgia State University), Theo A. ten Brummelaar (Georgia State University), Lewis C. Roberts, Jr.(The Boeing Company), Brian D. Mason (United States Naval Observatory), William I. Hartkopf (United States Naval Observatory), Douglas R. Gies (Georgia State University)
Keywords: O-stars
Abstract:
O stars are the most massive and luminous main sequence stars in the sky. They are frequently found in clusters of other O and B type stars. Due to the intrinsic brightness of these stars and their typical large distances, physical companions found by traditional techniques (spectroscopy, speckle interferometry, etc.) tend to be similar in mass and brightness to the primary. Adaptive optics observations allow one to probe for the fainter physical companions, further testing star formation scenarios and neighborhood conditions of O and B star clusters.
We present the results of a multi-year survey of O stars using AEOS, specifically searching for additional companions. Starting with a list of 171 O stars accessible to AEOS, we were able to observe 104 of these objects at least once, using the facility VisIm camera at I band. Under good atmospheric conditions, the analysis indicates that we can detect, and measure, a differential magnitude of at least 8 at I band, with indications that we may be doing better. Of these 104 systems, we have detected 38 new companions in 30 O star systems. We plan follow-up measurements of these 30 systems at the V and R bands, using a different, lower noise CCD camera.
Date of Conference: September 10-14, 2006
Track: Poster