Hyades

V-shaped cluster of stars that forms the face of the bull in the constellation Taurus. It is 150 light years away from the Sun, and contains over 200 stars, although only about 12 are visible to the naked eye.

The Hyades is a much older cluster than the Pleiades, for not only have some of the brighter stars evolved into red giants, some have gone even further and are now white dwarfs. Aldebaran, which marks the eye of the bull and which appears to be in the middle of the cluster, is not actually a member of the cluster. It is only 65 light years away from the Sun.

The Hyades is sometimes described as a ‘moving cluster’, as the proper motions of its members are large, are very nearly the same, and stand out conspicuously from those of the surrounding stars. They appear to converge, and thus provide an independent geometrical method of estimating the cluster's distance from the Earth. This is particularly important as the observed relationship between the absolute magnitudes and colours of its constituent members can be used to estimate the distances to more remote clusters, which in turn provide the scale with which all large intergalactic and extragalactic distances are measured.

Hyades

In Greek mythology, the group of nymphs who nursed and protected the young god Dionysus. In reward, they were changed into stars and placed in the constellation of Taurus.

They were called Hyades (Greek ‘rainy’) because their heliacal rising foretold wet weather.