Mizar Ba is one of the two stars of Mizar B, the fainter partner of Mizar seen in a telescope, itself a close pair revealed by its spectrum.
At a glance
| type | white star (class A) |
|---|---|
| distance from the Sun | 85.8 light-years (26.3 pc) |
| its light left it | 85.8 years ago |
| luminosity | 6.5 × the Sun |
| radius | 1.7 × the Sun |
| surface temperature | 8,000 K |
Read off the piece’s own catalogue, the same values it draws with.
About Mizar Ba
A small telescope splits Mizar into two: the brighter Mizar A and the fainter Mizar B. Like A, Mizar B turned out to be double when its spectrum was studied, showing the signature of two stars on a close orbit: Ba and Bb.
Mizar Ba is a white A-type star, smaller and less luminous than the two stars of Mizar A. The orbit of the Ba–Bb pair is slower than that of the A pair but still far too tight for any ordinary telescope to separate.
Mizar A and Mizar B orbit each other in turn, on a period long compared with a human life, and the whole group shares its motion through space with Alcor.
What you see in the piece
Fly to Mizar and B stands apart from A; Ba and Bb split only when you approach very close, since their orbit is far smaller than the gap between the two pairs.
Questions
What is Mizar B?
Mizar B is the fainter of the two stars seen in a telescope at Mizar. It is itself a close pair of white stars, Ba and Bb.
How bright is Mizar Ba?
It shines about 6.5 × the Sun, with a surface near 8,000 K.