Image #240709

The brightest star in the constellation of Scorpius is Antares (Alpha Scorpii) seen here as the yellow orb at left. Antares is a red supergiant, so large that if it were to replace our Sun then Antares’ outer edge would extend all the way out to between Mars and Jupiter. The exact size is not known since the star pulsates causing its radius to change as much as 19% larger or smaller. Antares is counting down to explode as a supernova in the next million years or so.

Near Antares is the globular cluster Messier 4 (M4) containing over 100,000 stars about 5,500 light-years away. Based on the large abundance of white dwarves (up to 40,000) in M4, it’s thought the cluster’s overall age is twice that of our solar system. M4 was discovered by Swiss astronomer Jean-Phillippe Loys de Chéseaux in 1746 and became #4 in Charles Messier’s famous astronomical catalog.

Another globular cluster can be seen faintly above and to the right of Antares as seen from the backyard on 6 July 2024.