Empirical Isochrone Construction Within Open Star Cluster Investigation

We compose systems of the empirical isochrones for single and binary stars with various components’ mass ratio q = M2/M1 (M2 - mass of the secondary component; M1 - mass of the primary component) in order to search for unresolved binary and multiple stars in open star clusters. We fit an empirical isochrone for single stars across the main sequence (MS) elements assigned with exploiting of HDBSCAN algorithm. Isochrones for binaries are obtained by shifting of this empirical isochrone on values determined with the usage of PARSEC theoretical isochrones. We consider the color-magnitude diagrams (CMDs) in Gaia photometric system and the two-index diagrams (TIDs) composed of bands in the visible and infrared wavelengths.