Digitized Sky Survey 2 image of Antares and Rho Ophiuchi region

Click on the image for full resolution (3.2 MB)

This is a Digitized Sky Survey 2 image of Antares and Rho Ophiuchi region. Antares is the brightest star in the constellation Scorpius and the 16th brightest star in the sky. Antares is a red supergiant and an irregular variable. Its name means "rival of Mars" (Ares and Mars being, respectively, the Greek and Roman gods of war), a reference to its similar appearance to the Red Planet. In fact, since Antares lies within a zodiacal constellation, which contains the apparent path of the Sun and planets, it is commonly mistaken for Mars. With a diameter of 800 million km, it would, if put in place of the Sun, reach about halfway to Jupiter. A fierce stellar wind blowing from the surface of Antares has resulted in a circumstellar gas cloud, which is illuminated by the light from a hot B-type companion star that, at fifth magnitude, hides within the supergiant's bright glare (separation 3", magnitude 6.5, period 900 years). Because it contrasts with the brilliant reddish primary, Antares B may appear green. Rho Ophiuchi three-star system is to the upper right, the 22 Scorpi trinary lies just above Antares (near the center bottom). The globular cluster M4 is to the right of Antares.
The full resolution image weighs 3.2 MB, so please be patient when downloading!
Credit: Caltech/DSS2/Wikisky.org; Processing: Jean-Baptiste Faure