Faint companion search to O-stars using the adaptive optics system on the 3.63-meter telescope on Haleakala

Abstract

We present results of our survey of faint companions to O-stars using the adaptive optics (AO) system on the 3.63-meter Advanced Electro-Optical System (AEOS) telescope at the summit of Haleakala, on the island of Maui. The AEOS telescope is part of the United States Air Force's Maui Space Surveillance Site. We have surveyed most of the O-stars brighter than V magnitude 8.0 in the declination range of -25 to +65 degrees for faint companions. We are using the I-band (800 nm central wavelength, 150 nm approximate FWHM) for the survey. This is done for two reasons: 1) the distinctly red filter will de-emphasize the O-star primary and enhance the faint (presumably redder) secondary, increasing the dynamic range; and 2) using I-band allows all of the shorter wavelength light to be sent to the AO system, increasing its performance for fainter stars. We describe the scientific results of our survey as well as the reduction process we used to generate relative photometric results from a 12-bit frame transfer camera with no native ability to generate a bias frame.