Heidelberg University | 2019 Feb 15
Heidelberg researchers verify this phenomenon using Gaia data from the Hyades
In the course of their life, open star clusters continuously lose stars to their surroundings. The resulting swath of tidal tails provides a glimpse into the evolution and dissolution of a star cluster. Thus far only tidal tails of massive globular clusters and dwarf galaxies have been discovered in the Milky Way system. In open clusters, this phenomenon existed only in theory. Researchers at Heidelberg University have now finally verified the existence of such a tidal tail in the star cluster closest to the Sun, the Hyades. An analysis of measurements from the Gaia satellite led to the discovery.
Open star clusters are collections of approximately 100 to a few thousand stars that emerge almost simultaneously from a collapsing gas cloud and move through space at about the same speed. Owing to a number of influences, however, they do begin to disperse after a few hundred million years. Among the factors working against the gravitationally bound stars is the tidal force of a galaxy, which pulls the stars out of the cluster. Tidal tails then form during the movement of the star cluster through the Milky Way. It is the beginning of the end of an open star cluster. ...
Hyades Tidal Tails Revealed by Gaia DR2 ~ Siegfried Röser, Elena Schilbach, Bertrand Goldman
- Astronomy & Astrophysics 621:L2 (Jan 2019) DOI: 10.1051/0004-6361/201834608
arXiv.org > astro-ph > arXiv:1811.03845 > 09 Nov 2018