The Stellar Population of h and chi Persei: Cluster Properties, Membership, and the Intrinsic Colors and Temperatures of Stars
Nov, 2009Citations per year
Abstract: (arXiv)
(Abridged) From photometric observations of 47,000 stars and spectroscopy of 11,000 stars, we describe the first extensive study of the stellar population of the famous Double Cluster, h and Persei, down to subsolar masses. Both clusters have E(B-V) 0.52--0.55 and dM = 11.8--11.85/ the halo population, while more poorly constrained, likely has identical properties. As determined from the main sequence turnoff, the luminosity of M supergiants, and pre-main sequence isochrones, ages for h Persei, Persei and the halo population all converge on 14 Myr. From these data, we establish the first spectroscopic and photometric membership lists of cluster stars down to early/mid M dwarfs. At minimum, there are 5,000 members within 10' of the cluster centers, while the entire h and Persei region has at least 13,000 and as many as 20,000 members. The Double Cluster contains 8,400 M of stars within 10' of the cluster centers. We estimate a total mass of at least 20,000 M. We conclude our study by outlining outstanding questions regarding the properties of h and Persei. From comparing recent work, we compile a list of intrinsic colors and derive a new effective temperature scale for O--M dwarfs, giants, and supergiants.References(98)
Figures(66)