The embedded star clysters in the nebulae vdB-RN 92 and Gy 3-7 in Canis Majoris R1

Abstract

We employed J, H and Ks photometry from the 2MASS Point Source Catalogue to study the embedded star clusters in the nebulae vdB-RN 92 and Gy 3–7, which are located in the molecular cloud Canis Majoris R1. We employed colourcolour and colour-magnitudes diagrams together with theoretical pre-main sequence isochrones to derive their fundamental parameters. Ages are based on the fraction of stars with anomalous colours, supposedly of types Herbig AeBe and T Tauri. The vdB-RN 92 cluster has an age of 5–7 Myr and the Gy 3–7 cluster ≈2 Myr. The average reddening values are AV = 4.4 and AV = 6.3, respectively for vdB-RN 92 and Gy 3–7. The distance found for vdB-RN 92 was 1.5 kpc which is, within uncertainties, compatible with previous estimates for the complex. Gy 3–7 also appears to be related to the CMaR1 complex. We conclude that CMaR1 is a very active star-forming site, now with four star clusters in early evolutionary stages.