SCYON Abstract

Received on January 10 2001

Interpretation of color-magnitude diagram of the open cluster Praesepe.

AuthorsA.V. Loktin, L.K. Malisheva.
AffiliationUral State University, 51, Lenin av., Ekaterinburg, 620083, Russia
Submitted toAstron. Zhournal (Russia)
Links Praesepe


On the base of published theoretical evolutionary tracks of stars of various masses the modeling of color-magnitude diagram of Praesepe cluster was performed. Computer program created for this purpose allows to build color-magnitude diagrams and luminosity functions of model clusters in the presence of double stars, dispersion of ages of cluster stars and their pre-main-sequence evolution. By the comparison of observed color-magnitude diagram with model one it was shown that inclusion of these effects is enough to interpret the structure of color - magnitude diagram of Praesepe cluster. The age dispersion of cluster stars of turn-off point mass is appear to be equal to 8 x 107 years. The fraction of double stars between cluster members is equal to 20%, the distribution of mass ratios q of double stars' components is uniform for q > 0.4 with marked deficiency of systems with smaller q. The letter allow to estimate the fraction of double stars by the direct star counts on the color-magnitude diagram.