The Overcontact Binary BO Arietis

Abstract New radial velocity and photometric data for BO Ari have been obtained, and Roche-based simultaneous analysis of RV and light curve data for the system has been accomplished using the 2003 version of the Wilson-Devinney code. Values for the masses and radii have been obtained: M1 = 1.34 (2) Mʘ, M2 = 0.26 (1) Mʘ, and R1 = 1.25 (2) Rʘ, R2 = 0.61 (2) Rʘ. For the luminosities the most likely values are L1 = 1.67 (15) Lʘ and L2 = 0.42 (4) Lʘ, each the mean of two values. There is poor agreement with earlier values by Gurol et al. (2015). During the light curve modelling, solutions were found with a small third light contribution, but the existence of the latter cannot be established unambiguously owing to the very close residuals of the different solutions. A third component was not found in the RV data within detection limits.