Time Series Observations of UX Ursae Majoris (Abstract)

Volume 34 number 2 (2006)

William R. Alexander

John Hall

Ty Nelson

Danielle Miller

Abstract

(Abstract only) CCD photometry of the variable star UX Uma (1332+52) was obtained using a 0.2 meter Schmidt-Cassegrain telescope. UX Uma is a binary star system consisting of a white dwarf primary star and a solar-type secondary star. Designated as a “nova-like” system, material is systematically being transferred from the secondary star to the primary. According to models, this material forms an accretion disc around the primary. As the dimmer secondary star moves in front of the brighter primary, eclipses can be observed. A sequence of two eclipses were systematically observed and analyzed for the first time in approximately ten years, according to AAVSO data. The orbital period was determined to be 0.196578 ± 0.000168 day. Preliminary results show that one of the eclipses observed can be classified as “peculiar” and suggests that the hot spot on the accretion disc dimmed during one of the recorded eclipse events. This could be due to the variation of the rate of material falling onto the accretion disc from the secondary star. These observations were conducted with the assistance of undergraduate astronomy students.