Mizar Bb is the partner of Mizar Ba in the close pair called Mizar B, a white star like its companion and one of the members of the Mizar–Alcor family.
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 Bb
Mizar Bb completes the pair inside Mizar B. The spectrum of Mizar B carries the light of two similar stars, which move around their common centre on a close orbit; Bb is the second of them, near its partner in type and brightness.
Systems like this are found far more often than single stars among stars of this kind, and Mizar is a textbook example of how a point of light can hide a nested structure: pairs within pairs.
Bb is a white A-type star, its colour set by a surface hotter than the Sun’s.
What you see in the piece
Fly to Mizar B and Bb parts from Ba only when you are very close; from Earth it is wholly hidden in the light of the pair.
Questions
How many stars are in Mizar?
Four: two in Mizar A (Aa and Ab) and two in Mizar B (Ba and Bb). Alcor and its red dwarf companion probably belong to the same system.
How far away is Mizar Bb?
It is 85.8 light-years (26.3 pc) from the Sun, with the rest of Mizar.