Akademik Veri Yönetim Sistemi
ASTRONOMISCHE NACHRICHTEN, cilt.326, sa.1, ss.43-51, 2005 (SCI-Expanded)
New BV light curves and times of minimum light for the short period W UMa system LO And were analyzed to derive the preliminary physical parameters of the system. The light curves were obtained at Ankara University Observatory during 5 nights in 2003. A new ephemeris is determined for the times of primary minimum. The analysis of the light curves is made using the Wilson-Devinney 2003 code. The present solution reveals that LO And has a photometric mass ratio q = 0.371 and is an A-type contact binary. The period of the system is still increasing, which can be attributed to light-time effect and mass transfer between the components. With the assumption of coplanar orbit of the third body the revealed mass is M-3 = 0.21M(circle dot). If the period change dP/dt = 0.0212 sec/yr is caused only by the mass transfer between components (from the lighter component to the heavier) the calculated mass transfer rate is dm/dt = 1.682 x 10(-7) M-circle dot /yr. The absolute radii and masses estimated for the components, based on our photometric solution and the absolute parameters of the systems which have nearly same period are R-1 = 1.30R(circle dot), R-2 = 0.85R(circle dot), M-1 = 1.31M(circle dot), M-2 = 0.49M(circle dot) respectively for the primary and secondary components.