Dubhe is the brightest star of the bowl of the Plough and the upper of the two Pointers, the stars that lead the eye across the sky to Polaris.
At a glance
| type | orange giant (class K) |
|---|---|
| distance from the Sun | 123 light-years (37.7 pc) |
| its light left it | 123 years ago |
| luminosity | 369 × the Sun |
| radius | 30.2 × the Sun |
| surface temperature | 4,600 K |
| constellation | Ursa Major (Great Bear) |
Read off the piece’s own catalogue, the same values it draws with.
About Dubhe
Dubhe is an orange giant of class K, much wider and more luminous than the Sun, its surface cooler than the Sun’s. It is a binary: a close companion orbits it, its presence known from the motion of the main star.
Its name comes from the Arabic for bear, from a longer phrase naming the back of the greater bear. It carries the letter alpha of Ursa Major. A line from Merak through Dubhe, extended, reaches Polaris, which makes the pair the most used signpost in the northern sky.
Unlike most of the Plough, Dubhe is not part of the Ursa Major moving group, the family of stars travelling together through space. It only happens to lie along the same line of sight.
What you see in the piece
Fly out from the Sun in the piece and Dubhe drifts away from the rest of the bowl: it sits at a different distance from the stars of the bowl and does not share their motion.
Questions
How do you find Polaris from Dubhe?
Follow the line from Merak through Dubhe, the Pointers at the end of the Plough’s bowl, and continue it until you reach Polaris.
How far away is Dubhe?
Dubhe is 123 light-years (37.7 pc) from the Sun; its light left it 123 years ago.