The Hyades Cluster
This time of year, many are familiar with and can find the constellation Orion and his three belt stars all in a row. However, just to the west of Orion is the constellation of Taurus the Bull with its own very recognizable “V” shape of stars called the Hyades star cluster forming the face of Taurus. Draw a straight line through Orion’s belt stars and they point to the Hyades. The Hyades cluster is the closest cluster of stars to our Sun and is bright enough that it has been known since prehistoric times, appearing in many star atlases of the 17th and 18th centuries, mentioned by many classical authors from Homer to Ovid and included in the mythology of the Greeks and Romans.
The Hyades cluster is classified as an open star cluster. An open cluster is a group of a few thousand stars that are formed from the same giant molecular cloud of gas and dust. They are loosely bound by mutual gravitational attraction. The Hyades cluster formed about 625 million years ago and lies about 150 light-years away. The central Hyades stars are spread out over about 15 light-years. It is a roughly spherical group of hundreds of stars sharing the same age, place of origin, chemical characteristics and motion through space. It is the brightest stars of this cluster that form the familiar “V” shape giving us the bull’s face. The stars of the “V” are at various distances in the cluster. Aldebaran, a red giant star, known as the eye of the bull is not associated with the Hyades Cluster. Aldebaran lies about 65 light-years away, much closer to our Sun.