vendredi 12 septembre 2008

Corona Australis 2

Is a small compact constellation nestled between Sagittarius and Scorpius, just east of Scorpion's stinger.
The constellation is quite old, and is said to represent the crown worn by the centaur Sagittarius (and sometimes known as "Corona Sagittarii").
Like a number of other constellations in the southern hemisphere, its Bayer stars are far from complete, and are rather faint as well.

Double stars:
Kappa2 and kappa1 Coronae Australis form a gorgeous fixed double, visible in most of North America (as far north as Vancouver and Winnipeg) but only part of Europe, generally south of Paris or Stuttgart, and not at all in the UK.
Kappa2 is the primary: 5.9, 6.6; 359º and separation 21.4".
h5014 is a close visual binary with an orbit of 191 years. These are two equal stars: 5.7, 5.7. Epoch 2000 values are PA 346º and separation 0.9".

Variable stars:
Corona Australis has no long-period variables, but there are several irregular variables of considerable interest. Two of these, TY and R, are found in the nebulosity NGC 6726/27/29 (see below).

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