· · · ·


The Bull

Constellation FamilyZodiac
Right Ascension3h20 to 5h58
Declination+1.1° to +30.9°
Area (sq deg)797
Brightest StarAldebaran
Optimum VisibilityDecember
Map of Taurus
Relative Galactic Position of Taurus

Taurus lies in exactly the opposite direction to the Galaxy's Core. At a point in this constellation not far from the star Elnath is the mathematically nearest approach of the Galaxy's rim, roughly 17,000 light years away.


This region of the sky has been seen as a bull's head and forelegs since classical times, and perhaps even earlier. The Greeks identified the bull form as none other than Zeus himself, in the shape he took to pursue Europa.


The brightest and best known of Taurus' stars is the orange giant Aldebaran, an irregular variable star that forms the 'eye' of the bull, and is relatively close to the Solar System at a distance of 65 light years. Also prominent in this constellation is first magnitude Elnath, a blue star that forms the tip of Taurus' northern horn.

Star Clusters

Taurus is home to two of the most important star clusters in the sky, both of which are clearly visible to the naked eye. The most famous of these is the Pleiades cluster, named after the daughters of Atlas and Pleione (who each have their own star within the cluster). The Pleiades is a relatively young cluster, whose blue stars are still emerging from their nursery of shimmering gas and dust. It contains about one hundred stars in total, but only a few of these are visible without a telescope. The Pleiades are more than 400 light years from Earth.

Less than half as far away (150 light years to be precise), is a cluster named for the half-sisters of the Pleiades, the Hyades. The Hyades cluster is so close that it covers a significant area of the sky: its diameter of 8° is about fourteen times that of the full Moon. The Hyades is very easy to locate, because its stars form the triangular 'face' of the bull, behind the unrelated 'eye' star Aldebaran.


Near Zeta Tauri, the star marking the tip of Taurus' southern 'horn', is the first object in Messier's catalogue, better known as the Crab Nebula. This is the rapidly expanding remnant of a supernova seen from Earth in the year 1054. The Nebula itself represents the material thrown out from the outer layers of a dying star, but what remains of the star's core still lies at the heart of the nebulous region. This is a neutron star spinning on its axis thirty times a second, of the type categorised as a pulsar.


Related Entries