Brachium is a cool red star in Libra whose Latin name means the arm, a star once counted as part of Scorpius before it was moved to the Scales.
At a glance
| type | red giant (class M) |
|---|---|
| distance from the Sun | 288 light-years (88.4 pc) |
| its light left it | 288 years ago |
| luminosity | 1,890 × the Sun |
| radius | 129 × the Sun |
| surface temperature | 3,350 K |
| constellation | Libra (Scales) |
Read off the piece’s own catalogue, the same values it draws with.
About Brachium
Brachium is a red star of class M, swollen to an enormous size. Its surface is cool, so it glows red, and its great size makes it vastly more luminous than the Sun. Like many such stars its brightness wavers slightly and irregularly.
It was long catalogued as a star of Scorpius before the boundaries were redrawn and it was assigned to Libra. Its name, Latin for the arm, recalls that history of shared stars between the two figures.
What you see in the piece
Its colour is its temperature: in the piece Brachium is a distinctly reddish point in Libra, beside the white of the two claws.
Questions
What kind of star is Brachium?
Brachium is a red giant (class M), with a surface temperature of 3,350 K and 129 times the Sun’s radius.