Analysis of Membership Probability in Nearby Young Moving Groups with Gaia DR2

Abstract

We analyze the membership probability of young stars belonging to nearby moving groups with Gaia DR2 data. The sample of 1429 stars was identified from “The Catalog of Suspected Nearby Young Moving Group Stars.” Good-quality parallax and proper motion values were retrieved for 890 stars from the Gaia DR2 database. The analysis for membership probability is performed in the framework of the LACEwING algorithm. From the analysis it is confirmed that 279 stars do not belong to any of the known moving groups. We estimated the U, V, W space velocity values for 250 moving group members, which were found to be more accurate than previous values listed in the literature. The velocity ellipses of all the moving groups are well constrained within the “good box,” a widely used criterion to identify moving group members. The age of moving group members are uniformly estimated from the analysis of the Gaia color–magnitude diagram with MIST isochrones. We found a spread in the age distribution of stars belonging to some moving groups, which needs to be understood from further studies.