Hyades (star cluster)

The Hyades is an open star cluster located in the constellation Taurus. It is one of the closest open clusters to the Solar System and one of the best-studied. Its bright stars form a distinctive "V" shape, marking the head of Taurus the Bull.

The Hyades is estimated to be about 625 million years old. Its distance is approximately 153 light-years (47 parsecs) from Earth, which has been accurately determined through various methods, including the converging point method and parallax measurements from the Hipparcos and Gaia missions.

The cluster contains hundreds of stars, although only a few are easily visible to the naked eye. These brighter stars are mostly red giants and main sequence stars of spectral type A and F. The cluster's member stars share a common proper motion through space, meaning they are moving together in the same direction and at the same speed.

The Hyades is physically related to the much more distant and older moving group called the Hyades Stream. These stars share similar space motions with the Hyades cluster but are spread across a much larger region of the sky.

The cluster is an important subject of astronomical study, providing insights into stellar evolution, cluster dynamics, and the age and distance scales of the universe. Its relatively close proximity allows for detailed observations and analysis of its member stars, making it a valuable benchmark for calibrating astronomical measurements. The brightest star in Taurus, Aldebaran, appears near the Hyades in the sky, but it is not a member of the cluster, as it lies much closer to Earth along the same line of sight.