α Scorpii

Alpha Scorpii is Antares, “the rival of Mars” binoculars. The name refers to its colour, a unique glittering metallic red. A giant star, it has a radius more than 300 times that of the Sun’s.

Antares is easily found in the mid-Spring skies, to the southeast of Spica. It makes a large triangle with Vega and Arcturus and is one of the pointer stars in the summer skies in the northern hemisphere: the summer pointers.

Antares is a binary, made difficult due to the brightness of the primary. It has a noted colour contrast—a red primary and greenish companion: 1.0, 5.4; 274º, 2.5".

Conveniently Antares occults often with the moon; it is during these nights of temporary absence that its companion is easiest to detect.

Sigma Scorpii, northwest of Antares, is a close binary (Sh 224): 3.1, 5.2; 244º, 0.5".

In this same field is the star cluster M4, visible to the naked eye under ideal conditions with an apparent magnitude of 5.8. Binoculars bring out some of the stars and telescopes make this a spectacular deep sky object, although its proximity to Antares may prove a problem.

All files associated with The Constellations Web Page are
© 1999-2014 by Richard Dibon-Smith.