Extended stellar systems in the solar neighborhood.

Author(s)
Verena Fürnkranz, Stefan Meingast, João Alves
Abstract

We report the discovery of a kinematically cold group of stars, located in the immediate neighborhood of the well-known star cluster Coma Berenices (Mel 111). The new group identified in tangential velocity space as measured by Gaia contains at least 177 coeval members distributed in two subgroups, and appears as a flattened structure parallel to the plane, stretching for about 50 pc. More remarkably, the new group, which appears to have formed about 300 Myr later than Mel 111 in a different part of the Galaxy, will share essentially the same volume with the older cluster when the centers of both groups will be at their closest in 13 Myr. This will result in the mixing of two unrelated populations with different metallicities. The phase of cohabitation for these two groups is about 20-30 Myr, after which the two populations will drift apart. We estimate that temporal cohabitation of such populations is not a rare event in the disk of the Milky Way, and of the order of once per Galactic revolution. Our study also unveils the tidal tails of the Mel 111 cluster.

Organisation(s)
Department of Astrophysics, Research Network Data Science
External organisation(s)
Harvard University
Journal
Astronomy & Astrophysics
Volume
624
No. of pages
7
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361/201935293
Publication date
04-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/35706e14-2401-49d5-8680-ef5e84501b83