Theoretical UBV colours of accretion discs in cataclysmic variables

The radiation of model stellar atmospheres with appropriate temperatures and gravities is integrated over the surface of the stationary and optically thick accretion disc. The UBV colours of the disc are obtained and compared with observations of some close binary systems containing luminous discs. A rough estimate of the amounts of matter flowing through the disc appears to be possible. However, the agreement between the observed and computed colours is not very good. The necessity of taking into account the emission from the optically thin parts of the disc seems to be inevitable. (author)