ANTARES

also called Alpha Scorpii red, semiregular variable star, with apparent visual magnitude about 0.9, the brightest star in the zodiacal constellation Scorpius and one of the largest known stars, having several hundred times the diameter of the Sun and several thousand times the Sun's luminosity. It has a fifth-magnitude blue companion. Antares lies about 400 light-years from the Earth. The name seems to come from a Greek phrase meaning rival of Ares (i.e., rival of the planet Mars) and was probably given because of the star's colour and brightness.