Mizar Ab is one of the two white stars that make up Mizar A, a pair so tight that only the spectrum, not a telescope, revealed it was double.
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 | 33 × the Sun |
| radius | 2.4 × the Sun |
| surface temperature | 9,000 K |
Read off the piece’s own catalogue, the same values it draws with.
About Mizar Ab
Mizar, in the handle of the Plough, was among the first double stars seen through a telescope: Mizar A and Mizar B. Later, Mizar A became the first star found to be double from its spectrum alone. Its lines split and merged on a regular schedule as two stars, Aa and Ab, swung towards and away from us.
Mizar Ab is the second of those two white A-type stars, similar to its partner and orbiting it on a fast, close orbit. Interferometers have since resolved the pair directly, confirming what the spectrum implied.
With Mizar B, itself a spectroscopic pair, and Alcor with its own companion, Mizar Ab belongs to a family of six stars that appear to travel together.
What you see in the piece
Fly to Mizar and Ab separates from its partner only when you are very close; from Earth the two merge into the single white point of Mizar A.
Questions
Is Mizar a multiple star?
Yes. Mizar is two pairs: Mizar A is two white stars, Aa and Ab, and Mizar B is two more, Ba and Bb. With Alcor and its companion, the system may count six stars.
How far away is Mizar?
Mizar is 85.8 light-years (26.3 pc) from the Sun.