Absolute parameters for binary systems

I. The active binary BH Virginis

¹ Departamento de Astronomía y Astrofísica, Universidad de Valencia, Dr Moliner 50, E-46100, Burjassot, Valencia, Spain e-mail: clement@deneb.matapl.uv.es
² Departamento de Física Aplicada, E.U.I. Industrial, Universidad Politécnica de Madrid, Ronda de Valencia 3, E-28012 Madrid, Spain

Send offprint request to: R. Clement

Received: 12 September 1996
Accepted: 6 December 1996

Abstract

New high-quality light curves of the late-type binary system BH Vir have been obtained during a 6 year photometric uvby and monitoring program of low mass eclipsing binaries (Clement et al. 1997), hereafter Papers I and II. This paper presents detailed analysis of this binary based on the four light curves obtained within our program. The activity wave superimposed on the eclipse-modulated light curves has been adjusted and removed by using a new iterative application of the standard EBOP code together with truncated Fourier Series fittings. Combining the recent radial velocity curves (Popper 1995) with the geometrical elements deduced from the "clean" photometric light curves, the absolute parameters of the system are calculated. BH Vir appears as a binary composed by two main sequence G0 and G2 stars with solar chemical composition lying on the same isochrone ( years). The accuracy obtained on the absolute parameters determination allows us to include BH Vir on the select group of late-type stars to be used on the estimation of the Mass-Luminosity-Relationship.