Antares

Antares is a red supergiant star located in the southern constellation Scorpius. It is the brightest star in Scorpius and one of the brightest stars in the night sky, with an apparent visual magnitude around 1.0. The name Antares derives from Greek and means “rival of Ares” (Mars).

Antares lies at roughly 550 light-years from Earth (about 170 parsecs). Its spectral type is M1.5Ia–Ib, indicating a luminous red supergiant. It is a semi-regular variable star whose brightness varies modestly over time.

The star has a radius around 680 solar radii, a mass estimated at about 12–15 solar masses, and a luminosity of roughly 100,000 times that of the Sun. Its surface temperature is about 3,500–3,600 kelvin, which gives it its characteristic reddish-orange color.

Antares loses mass vigorously through a strong stellar wind, creating an extensive circumstellar envelope and dust shell. Interactions with the surrounding interstellar medium produce features such as a bow shock and infrared nebulosity in the system.

As a prominent example of a late-stage, red supergiant, Antares is a key object in studies of stellar evolution and mass loss. It is a notable anchor in the southern sky and a frequent reference point in catalogs of bright stars.