Near-infrared JH photometry of young open cluster Be 59

Abstract

We present near-infrared JH photometry and optical slitless spectroscopy of stars in the field of the young cluster Be 59. The J/(J − H) colour-magnitude diagram of the cluster yields a distance modulus of (m − M )0 = 10.0 ± 0.2 mag, which corresponds to a distance of 1.0 ± 0.1 kpc. Using the slitless spectroscopy we identified 9 Hα emission line stars in the observed region. The location of Hα stars in the CMD indicates that they may be pre-main sequence stars. We have estimated the age of the cluster using the turn-off and turn-on points and is found to lie between ∼ 1 Myr to 4 Myr. Two massive stars (∼ 25 M☉ ) in the cluster region have high membership probability which indicates that the low mass stars (∼ 0.8 M☉ ) may co-exist with massive stars.