Constellation for January 2023 – Taurus
Taurus, an ancient constellation, represents a bull which is charging the hunter Orion directly underneath it; it is below another hero, Perseus. The bull’s horns are Tianguan (Zeta Tauri) and Elnath which belongs to both Taurus and Auriga. Its head is the triangle of stars which contain the bright orange star Aldebaran, which represents the angry bull’s bloodshot eye. The shape of its front body (we do not see its rear) is two lines from the triangle; one to Atlas in the Pleiades and the other to Omicron Tauri.
Taurus contains two famous star clusters: the
Pleiades
[1] and the
Hyades
[2]. They are both supposed to be naked-eye clusters, but only the Pleiades (Messier 45) is easily seen in Havering. I have only once seen the Hyades with the naked eye on an exceptionally clear frosty night and it looked like a twisted triangle. Even in the telescope or binoculars it looks like a 50p coin-shaped asterism rather than a cluster. The Pleiades is a young cluster (115 million years old) and the Hyades is an old one (625 million years old), which is why it is less cluster-like. The Hyades is 153 light years away, but the Pleiades are three times more distant at 444 light years.
The other famous sight in Taurus is the
Crab Nebula [3], a cloud of gas with very hot filaments. It is at the great distance of 6,500 light years away. The Crab Nebula (also called Messier 1) is the expanding remains of a supernova explosion which was seen by the Chinese in 1054. At its centre is a pulsar which was discovered by Jocelyn Bell Burnell in 1968. It is fairly easy to see in a small telescope, just above Tianguan and it does look like a crab edge-on with an oval body and the bright filaments forming its claws.
The best double star in Taurus is 118 Tauri, a magnitude 5.4 star roughly half-way between Elnath and Tianguan. The companion star is magnitude 6.7 and the separation is 4.6 arcseconds; they are both yellowish. Tau Tauri is a bright double star, whose stars are magnitude 4.2 and 7.0 with a separation of 62.5 arcseconds; their colours are white and lilac. Just north-west of Ain is T Tauri, which is a very young star and is next to Hind’s variable nebula (NGC 1555). It is faint (magnitude 9.8), but it can be located by finding two triangles of stars above Ain (see map at top of page).
