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 premain 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.