Proper Motion
The stars of the Hyades are more enriched in heavy elements than our Sun and other ordinary stars in the Solar neighborhood, with the overall cluster metallicity measured at +0.14.
The Hyades Cluster is related to other stellar groups in the Sun's vicinity. Its age, metallicity, and proper motion coincide with those of the larger and more distant Praesepe Cluster, and the trajectories of both clusters can be traced back to the same region of space, indicating a common origin. Another associate is the Hyades Stream, a large collection of scattered stars that also share a similar trajectory with the Hyades Cluster. Recent results have found that at least 15% of stars in the Hyades stream share the same chemical fingerprint as the Hyades cluster stars. However, about 85% of stars in the Hyades Stream have been shown to be completely unrelated to the original cluster on the grounds of dissimilar age and metallicity; their common motion is attributed to tidal effects of the massive rotating bar at the center of the Milky Way Galaxy. Among the remaining members of the Hyades Stream, the exoplanet host star Iota Horologii has recently been proposed as an escaped member of the primordial Hyades Cluster.
The Hyades are unrelated to two other nearby stellar groups, the Pleiades and the Ursa Major Stream, which are easily visible to the naked eye under clear dark skies.
Read more about this topic: Hyades (star Cluster)
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