Antares is the red supergiant at the heart of Scorpius, a swollen, dying star so large it would swallow the orbit of Mars, with a hot companion.
At a glance
| type | red supergiant (class M) |
|---|---|
| distance from the Sun | 554 light-years (170 pc) |
| its light left it | 554 years ago |
| luminosity | 75,900 × the Sun |
| radius | 680 × the Sun |
| surface temperature | 3,660 K |
| constellation | Scorpius (Scorpion) |
Read off the piece’s own catalogue, the same values it draws with.
About Antares
Antares is a massive star near the end of its life, expanded to an enormous size with a cool, red surface. Its name means rival of Mars, because the two look alike in colour and Mars passes near it. Interferometers and radio telescopes have mapped its surface and its vast, extended atmosphere.
It has a companion, Antares B, a hot blue-white star that orbits far out. Next to the glare of the supergiant it is hard to see; it is often described as greenish, an effect of contrast with the red star. It is easiest to glimpse when the Moon passes in front of Antares.
Antares belongs to a group of young, massive stars in Scorpius and Centaurus. Stars like it end in a supernova.
What you see in the piece
With HUMAN EYE on it is the bright red heart of the scorpion. Fly to it and the disc fills the view, deep red; the WONDERS (W) include it with Antares B, small and blue-white beside it.
Measured or modelled
Its exact size depends on where its surface is taken to be, since its atmosphere thins out gradually. When it will explode cannot be predicted closely, beyond being far in the future on any human timescale.
Questions
How big is Antares?
Antares has a radius of 680 × the Sun; placed at the Sun’s position, it would reach beyond the orbit of Mars.
Does Antares have a companion?
Yes. Antares B is a hot blue-white star in orbit around it, hard to see in the supergiant’s glare.