Title : " Short Time Scale Variation of a Near-Contact Binary System, GR Tauri"

Researcher : Boonruksa Soonthornthum, Y. Yang, L. Qingyao and B. Tanvanichkul

Office of Researcher : PHYSICS


A near-contact binary system, GR Tauri, was observed photometrically in V wavelength band in November 1995 at the Yunnan Observatory. The asymmetric light curve was found in this observation, where the maximum at phase 0.25 is brighter than the maximum at phase 0.75 by 0.02 magnitude.

Analysis for its physical properties and orbital elements was done by using Wilson-Devinney code. The model found is a semi-detached binary system with the secondary component almost filling its critical Roche lobe while the primary component fills it completely. The results show the evidence of a short time scale variation of this binary system.

Presented at 1999 Pacific Rim Conference on Stellar Astrophysics, University of Hong Kong, Hong Kong, 2-7 August 1999.