Extended stellar systems in the solar neighborhood – III. Like ships in the night: the Coma Berenices neighbor moving group. (arXiv:1902.07216v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Furnkranz_V/0/1/0/all/0/1">Verena Fürnkranz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Meingast_S/0/1/0/all/0/1">Stefan Meingast</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alves_J/0/1/0/all/0/1">João Alves</a>
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). To the limit of our sensitivity, the new group contains at least 162
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, formed about 400 Myr ago, will share the same volume as the Mel 111
cluster when the centers of both groups will be at their closest in 14 Myr.
This will result in the mixing of two unrelated coeval populations, with
different metallicities, that formed 300 Myr apart in different parts of the
Galaxy. 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.
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). To the limit of our sensitivity, the new group contains at least 162
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, formed about 400 Myr ago, will share the same volume as the Mel 111
cluster when the centers of both groups will be at their closest in 14 Myr.
This will result in the mixing of two unrelated coeval populations, with
different metallicities, that formed 300 Myr apart in different parts of the
Galaxy. 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.
http://arxiv.org/icons/sfx.gif
