Aldebaran is the orange giant that marks the eye of Taurus, seemingly part of the Hyades cluster but in fact much closer, lying in front of it.
At a glance
| type | orange giant (class K) |
|---|---|
| distance from the Sun | 65.2 light-years (20 pc) |
| its light left it | 65.2 years ago |
| luminosity | 439 × the Sun |
| radius | 45.1 × the Sun |
| surface temperature | 3,910 K |
| constellation | Taurus (Bull) |
Read off the piece’s own catalogue, the same values it draws with.
About Aldebaran
Aldebaran is a giant star that has exhausted the hydrogen in its core and expanded to many times the Sun’s width, cooling to an orange colour. It is one of the brightest stars in the sky and the eye of the bull in the constellation of Taurus.
On the sky it sits among the V-shaped Hyades, the nearest open cluster, but it is not a member: it lies much nearer to us than they do, and the two only line up by chance. Aldebaran is close to the path of the Moon, so it is regularly hidden, or occulted, by the Moon, and the timing of those events has been used to measure its size.
What you see in the piece
With HUMAN EYE on it is an orange point at the tip of the Hyades V. Fly out towards Taurus and the cluster pulls away behind it, showing how far apart they truly are. Fly to it and the planet listed for it in planet catalogues is drawn on its orbit, disputed as it is.
Measured or modelled
A giant planet was proposed from small periodic changes in its spectrum, but such signals in giant stars can also come from pulsations or surface activity, and the planet is not confirmed.
Questions
Is Aldebaran part of the Hyades?
No. It lies in front of the Hyades, much closer to us, and only appears among them from Earth. Aldebaran is 65.2 light-years (20 pc) from the Sun.