Cosmic Scale
Aldebaran
Red giant · 65 light-years
How big is Aldebaran?
Aldebaran is about 6.1 × 10⁷ km across.
See Aldebaran in 3D, at true scale
Aldebaran is the red eye of Taurus the Bull, an orange giant that has swollen to 44 times the Sun's width. It appears to sit among the Hyades star cluster but is actually less than half as far away.
At a glance
| Diameter | 6.1 × 10⁷ km |
|---|---|
| Mass | 2.31 × 10³⁰ kg |
| Diameter compared with Earth | 4,820 × Earth |
| Distance | 65 light-years |
| Surface | 3,900 K |
| Brightness | 440 Suns |
| Type | Red giant |
Good to know
- The Pioneer 10 probe is drifting toward it and will arrive in roughly two million years.
- Its name comes from Arabic for 'the follower', because it trails the Pleiades across the sky.
- It is bright enough that the Moon regularly passes in front of it, which is how its size was first measured.