| Antares (Alpha Scorpii; a Sco) |
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The brightest star in the constellation Scorpius. It is a red supergiant M star of magnitude 1.0. The name is derived from Greek, meaning "rival of Mars" - a reference to its noticeable colour. It is a semiregular variable star, fluctuating between magnitudes 0.9 and 1.1 over a five-year timescale. It has a sixth magnitude blue companion only 3 arc seconds away. See also: Table 3. |