AAVSO: American Association of Variable Star Observers
Login

Over-Contact Binary GR Tauri (Poster abstract)

Volume 37 number 2 (2009)

Lee Snyder

Abstract

(Abstract only) New times of minima and ephemerides are presented on the over-contact system GR Tauri. An observed minus calculated (O–C) time of minimum chart was constructed, and, based on statistical analysis, the orbital period of the system is found to be decreasing with a rate of dP/dE = 3.33–4 seconds/year–1 since 1931. Both components are filling their respective critical Roche lobes with fillouts f = 0.11 and 0.95. The light curve displays the O’Connell effect, which is discussed on the assumption mass is going from the primary to the secondary creating a hot spot. The thermal relaxation oscillations (TRO, Lucy and Wilson 1979), theory is discussed as an explanation.