Open Cluster M39: This bright group of stars in a distance of 1000 LY can be detected in the constellation of Cygnus or the Swan even with unaided eyes. The brightest stars of the Open Cluster stand out from a dense star background of the Milky Way. All the cluster stars are still on the main branch of the HRD, thus the age is in the order of 300 - 500 Million years.