A multicolor photometric study of the neglected eclipsing binary FT Ursae Majoris

The multicolor photometric observations of the neglected eclipsing binary FT Ursae Majoris (FT UMa) were obtained in 2010. The 2003 version of the Wilson-Devinney code was used to analyze the light curves in the B, V and R bands simultaneously. Based on the spectroscopic mass ratio q = 0.984 published by Pribulla et al., it is found that FT UMa is an evolved contact binary with a contact degree of 15.3%. The low amplitude of light variations, ∼ 0.15 mag, arises mainly from a moderately low inclination angle of i = 62.800 and almost identical components in size rather than the light dilution of a third component, which contributes light of only ∼ 10%. (research papers)