Eclipsing binaries and the mass-luminosity relation

Institute of Astronomy of the Russian Acad. Sci. 48 Pyatnitskaya St., Moscow 119017, Russia Observatoire de Besançon, 41bis avenue de l'Observatoire, 25010 Besançon, Cedex, France Isaac Newton Institute of Chile Moscow Branch

Corresponding author: malkov@inasan.ru

Received: 20 January 2003
Accepted: 25 February 2003

Abstract

We have compared radii of eclipsing binary components and single stars. We have found a noticeable difference for B0V–G0V components of eclipsing binaries and single stars of the corresponding spectral type. This difference can be confirmed by a re-analysis of results of other published investigations and, in particular, it can explain the disagreement between published scales of bolometric corrections.
According to our results, A- and F-type main sequence eclipsing binaries have larger radii and/or higher temperatures than single stars while B-type eclipsing binaries have smaller radii. Possible explanations for these features are proposed.
We have concluded that the mass-luminosity relation based on empirical data of eclipsing binary components cannot be used to derive the stellar initial mass function. While our current knowledge of the empirical mass-luminosity relation for masses more than  is based exclusively on eclipsing binaries data, accurate observational data for a few hundred visual binaries of intermediate and high masses should be collected. Then the initial mass function for this mass range should be revised.