BVRI Photometry of W Ursae Majoris Binary Systems and Lessons Learned (Abstract)

Volume 38 number 1 (2010)

Andy Howell

Abstract

(Abstract only) Six years ago, a multi-color BVRI survey of W UMa binary systems was begun. This was the first time the author undertook multi-color photometry. Although he had done V-band photometry in the past, there were many new things he had to learn. Data of thirty-five W UMa binaries was collected on nine nights during Nov/Dec 2003 when the sky was suitable for all-sky photometry. The equipment used was an 11-inch Schmidt-Cassegrain with ST-9E camera and BVRI filters. Approximately 1,520 CCD images were obtained. The data then waited six years to be reduced. A major reason for the delay was overcoming procrastination in reducing this rather large data set. An efficient, accurate process had to be developed. First, Mira AL was used to extract the instrumental magnitudes. Then, the data were entered into a filemaker pro relational database where air mass values were obtained from the AAVSO web site. The final step in the reduction process was to use Minitab statistical software to transform instrumental magnitudes into standard magnitudes. Publication of the scientific results is forthcoming. This work was partially supported by a grant from NASA administered by the American Astronomical Society.