Physical parameters of the Algol system BP Muscae from simultaneous analysis of Geneva 7-colour light curves

Abstract

Abstract. The semi-detached eclipsing binary system BP Muscae has been analysed using the Wilson-Devinney program. Light curves have been obtained in the G 7-colour photometric system, and radial velocity curves for both components have been measured with the spectrograph C. The physical and orbital parameters have been determined through a selfconsistent simultaneous solution of light curves in seven colours and of the radial velocity curves of both components. The absolute elements of the components are, for the primary (mass gainer), M 1 = 2.40 ± 0.01 M , R 1 = 2.64 ± 0.01 R , M bol 1 = 0.66 ± 0.04, T eff 1 = 9180 ± 90 K, and for the secondary (mass loser), M 2 = 0.68 ± 0.01 M , R 2 = 3.76 R , M bol 2 = 2.40 ± 0.08, T eff 2 = 5160 ± 90 K. The semi-major axis A of the relative orbit is 13.617 ± 0.019 R . The spectral type of the components are A0.5/1.5 V (primary) and about G5 III. The distance to BP Mus is evaluated as 562 ± 17 pc, and the colour excess E[B2-V1] as 0.220 ± 0.014.