We have presented an accurate determination of absolute parameters for the
binary system BH Vir, based on new good-quality 
light curves and
new spectroscopic determination of mass ratio.
Before going into the analysis of the light curves we cleaned them of the contribution of the intrinsic activity, using a new iterative process that combines the wave determination with the binary solution search.
The effectiveness of this method, physically correct, is clearly seen looking at the reduction of the dispersion of the light curve outside eclipses which contains points from four different epochs of this highly variable binary system.
The geometric and photometric results agree well with the ones published by other authors but the precision attained in this work is one order of magnitude better. However the masses and radii derived in this paper are slightly different, since we used new and more accurate values for the amplitudes of the radial velocity curve, combined with the high accurate determination of the geometrical parameters from the photometric light curves. The secondary eclipse is total within the uncertainty of our analysis supporting the result of Vincent (1993).
So we can conclude that BH Vir is a binary composed by two main sequence stars of spectral type G0 and G2 that undergo total eclipse. The high level of activity which is variable with time has been removed from the light curve and then its absolute astrophysical parameters computed precisely.
This results allow us to include BH Vir on the select group of late-type binaries to be used on the computations of Mass-Luminosity Relationship (MLR).
Acknowledgements
The 1.5 m telescope at Calar Alto is operated by the Observatorio Astronómico Nacional. The 0.5 m telescope is operated by the Copenhagen Group. We want to express our gratitude to the observatories staff. This work has been supported by the Spanish Comisión Interministerial de Ciencia y Tecnologıa (PB90-0001-C02)