Alkaid is the star at the end of the Plough’s handle, a hot blue-white star that, unlike most of the figure, does not travel with its neighbours.
At a glance
| type | blue-white star (class B) |
|---|---|
| distance from the Sun | 104 light-years (31.9 pc) |
| its light left it | 104 years ago |
| luminosity | 797 × the Sun |
| radius | 2.69 × the Sun |
| surface temperature | 18,700 K |
| constellation | Ursa Major (Great Bear) |
Read off the piece’s own catalogue, the same values it draws with.
About Alkaid
Alkaid is a blue-white star of class B, the hottest of the Plough’s seven bright stars and far more luminous than the Sun. Hot, massive stars like it burn through their fuel quickly, so it is young on the cosmic scale.
Its name comes from the Arabic for the leader: in an old Arabic picture the bowl of the Plough was a bier and the handle the mourners walking ahead of it, with Alkaid at their head. An older form of the name, Benetnasch, comes from the same image.
Alkaid and Dubhe are the two stars of the Plough that are not members of the Ursa Major moving group, so over very long ages they will drift away and the familiar shape will change.
What you see in the piece
Seen from Earth Alkaid ends the handle neatly. Fly out and it parts from Mizar and Alioth, which belong to a group moving together through space while Alkaid goes its own way.
Questions
Which star is at the end of the Big Dipper’s handle?
Alkaid, a blue-white star (class B) 104 light-years (31.9 pc) from the Sun.