Genitive: Coronae Australis
English: The Southern Crown
Size Ranking: 80th
Area: 128 square degrees
Fully Visible: 44°N – 90°S.
Corona Australis, The Southern Crown is the southern counterpart of the Northern Crown Corona Borealis and unlike many of the southern constellations, of which it is part, has been known since the time of the Greek astronomer Ptolemy. In the 2nd century AD, Ptolemy visualized this constellation not as a crown but as a wreath. In one legend it represents the crown placed in the sky by Bacchus when he rescued his dead mother from the Underworld. Alternatively it is suggested that Corona Australis is the crown that slipped from the head of the centaur Sagittarius to land at his feet. Although faint it is a distinctive figure situated on the edge of the Milky Way.
A suggested way of locating Corona Australis is to imagine a line passing through the two Pointers, which are adjacent to the Southern Cross, and extending that line out to the left by a distance nine times the distance between the two Pointer stars to the area of the sky containing this constellation. The tail of Scorpius will be seen just slightly up and to the right.
Features of Interest:
αCrA is a blue-white main sequence star of magnitude 4.1 and is 130ly away.
βCrA is 510ly distant and is a 4.1 magnitude orange giant.
γCrA consists of a binary pair of near identical yellow-white stars, of magnitudes 4.9 and 5.0, separation 1.3”(?), PA 109°, orbiting every 122 years. They are 58ly away and form a tight double for smaller telescopes.
κCrA is a pair of unrelated blue-white stars of magnitude 5.7 and 6.3, at respective distances of 1700 and 490ly, separation 21.6”, PA 359°. As such, they are readily divisible.
λCrA is a blue-white star ,202ly away, of magnitude 5.1, with a 9.7 companion, separation 29.2”, PA 214°. They should be visible in smaller telescopes.
NGC 6541 is a 7th magnitude globular cluster, a mere 22,000ly away, visible in binoculars and small telescopes. It covers an area about one third the apparent size of the full Moon.
1. Redshift 2 – Maris Multimedia
2. The Guinness Book of Astronomy – Patrick Moore
3. Stars and Planets – Ian Ridpath and Wil Tirion
4. Sky Charts – Cartes du Ciel V 2.75.