Extended stellar systems in the solar neighborhood - the Hyades tidal tails and beyond

Stefan Meingast, Joao Alves, Verena F├╝rnkranz

Already the first few years of the Gaia mission have brought a wealth of new insights into the velocity distribution of the stellar population in the solar neighborhood. While the complex ridge-like pattern in the large-scale velocity distribution seems to be caused by non-axisymmetric components of the Galaxy, we can find stellar clusters and groups imprinted as small-scale fluctuations on those larger ridges in velocity space. One prominent representative of these groups is the nearest open cluster to the Sun, the Hyades. In this contributed talk, I showed how Gaia enabled the remarkable confirmation of the long-predicted tidal tails of the Hyades open star cluster. In particular, I highlighted the striking similarity to the predicted shape of the tidal tails, as well as the expected velocity dispersion profile of the cluster. Looking beyond the Hyades, I highlighted the richness of the solar neighborhood in kinematically cold stellar associations and clusters. The structure and spatial arrangement of these groups outlines a highly dynamic evolution in the global gravitational potential of the Galaxy. Most notably, these results favour a picture where star clusters, that are bound in the Galactic disk, are, given time, transformed into thin, dynamically-cold streams of stars, their shapes reminiscent of tidally disrupted globular clusters.

Department of Astrophysics
Publication date
Austrian Fields of Science 2012
103004 Astrophysics, 103003 Astronomy
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