Monday 13 December at 3pm

Douglas Caldwell - NASA Ames Research Center

"Photometric Detection of Extrasolar Planets with the Vulcan Camera"

ABSTRACT: "The NASA Ames Research Center's Vulcan photometer is a small wide-field-of-view CCD camera used to monitor thousands of stars for transits by extrasolar planets. The current configuration consists of a 300mm f/2.8 Canon lens, and a 4096x4096 pixel front-illuminated CCD with 9 micron pixels, giving a 7x7 degree field-of-view. The camera is installed in a dedicated dome at Lick Observatory in California. Our group makes observations of a single field, containing 6000-8000 9th-12th magnitude target stars, nightly for eight to twelve weeks. We currently achieve 0.2 - 0.8% hour to hour relative photometric precision, sufficient to detect transits by Jupiter-sized planets around Solar-like stars. To date we have substantial data on three Galactic plane fields. We have detected nearly one hundred variable stars per field, approximately half are eclipsing binaries with eclipse depths ranging from 50% down to ~1%. From one of the fields, several stars with photometric signals consistent with planetary transits were observed with high-resolution spectroscopy and found to be eclipsing binaries. We are continuing with photometric observations and data analysis, as well as follow-on observations for other candidate stars."