Gaia DR3 Data of Very Young Open Cluster NGC 6530: Distance and Evolutionary Stage of Selected Stars

Abstract

Gaia EDR3 and Gaia DR3 data of selected stars in the very young (1.5-million-year-old) open cluster NGC 6530 are presented. All the selected stars have very accurate Gaia DR3 distances. Most of the selected stars are very young B stars and several of them are young stellar objects (YSO). From the analysis of selected stars, the distance to NGC 6530 is found to be 1318 pc. The two very red stars VAJ 304 and 338 have little bit less proper motion than other members of the NGC 6530 and their Mv values are found to be -3.57 and -3.68 respectively. They are much brighter than K5 III RGB stars and less luminous than massive K5 red supergiants. It is likely VAJ 304 and VAJ 338 are not members of NGC 6530 they may be field K5 type AGB or postAGB stars. Further study of these two stars is needed.