Antares A is the cool red M1.5Iab-Ib supergiant primary of a double star system. The effective temperature is about 3100 K. The star is approximately 10,000 times as luminous as the sun. Acccording to Burnham Antares A would have a mass of 10 to 15 times that of the sun.
This huge star has a radius that is probably almost 4 AU. If the sun were replaced by Antares A at the center of the solar system, the earth would be engulfed, as would be Mars and the Asteroid Belt. Jupiter would orbit about 1 AU from the surface of the star!
The companion star is a hot blue B4Ve main sequence star. The spectral type implies an effective temperature of 18,000 K.
The companion Antares B is itself larger than the sun, with a diameter about 4 times that of the sun and a mass almost 10 times that of the sun. This star would be about 1900 times as luminous as the sun.
According to the The Bright Star Catalog the orbital period of the two stars about their common center of mass is 878 years. The semimajor axis of the orbit is 2.90 sec of arc corresponding to 540 AU at the distance of the stars. This is about 14 times the radius of the solar system out to Pluto.
Study of the dynamics of the orbit implies a mass of 15.5 times the sun for Antares A and a mass of 7.0 times the sun for B.