Antares
Star
Antares — a colossal red supergiant marking the heart of the Scorpion, roughly 550 light-years away (the distance is uncertain). Hundreds of times the Sun's diameter, its deep red glow rivals Mars — which is exactly how it got its name — and it too will one day explode as a supernova.
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Key facts
Mass
2.39 × 10³¹ kg
12 M☉
Radius
3.16 AU
680× wider than the Sun
Surface temperature
3,660 K (3387 °C)
Luminosity
2.87 × 10³¹ W
Spectral type
M1.5 Iab-Ib (red supergiant)
Science
Physical
- Mass
- 2.39 × 10³¹ kg · 12 M☉
- Radius
- 3.16 AU · 680× wider than the Sun
- Density
- 0.0000538 kg/m³ · 5.4e-08× water
- Spectral type
- M1.5 Iab-Ib (red supergiant)
Composition
- By mass
- A cool, enormous red supergiant hundreds of times the Sun's diameter, paired with a hot blue main-sequence companion (Antares B). Late in its life, it will end as a supernova. Its deep red colour rivals Mars, from which it takes its name. The distance (~170 pc) is genuinely uncertain, as parallax is hard for so large and remote a star.
Temperature
- Surface
- 3,660 K (3387 °C)
Radiation & temperature
- Surface temperature
- 3,660 K (3387 °C)
- Peak wavelength
- 792 nm · near-infrared (mostly invisible to the eye)
Discovery & history
- Method
- Naked-eye star
- Name
- 'Antares' — 'rival of Ares (Mars)', for its red colour; Alpha Scorpii, the heart of the Scorpion (Cor Scorpii).
Known since antiquity as the Scorpion's heart; the Greeks named it for its Mars-like colour. A hot blue companion, Antares B, has been resolved telescopically and glimpsed when the Moon briefly occults the bright primary.
Images
Images from open archives · credit shown per image