2378 20160701171704.0 ASTROimport-535 Lampens, P. 1997 On the Mass-Luminosity Relation Hipparcos has provided a lot of new data about double stars including accurate relative positions, magnitudes of the components and parallaxes. A couple of hundreds of visual binaries with relatively well known orbits and accurate parallaxes have been heavily selected in order to determine or improve their component masses by making use of these new data. On the other hand, additional colour information allowed us to obtain the conversion between Hipparcos and bolometric magnitudes. Using this together with available ground-based colours and spectral types for our sample of visual binaries, we were able to derive component luminosities. This increase in the stellar mass material was subsequently used to re-assess the currently adopted mass-luminosity relations. Kovalevsky, J. Froeschle, M. Ruymaekers, G. IAU Joint Discussion 14 1997 http://esoads.eso.org/abs/1997IAUJD..14E..42L published in NONREF