samedi 6 septembre 2008

Lupus 1

Lupus is a southern constellation.

Lupus has no extremely bright stars, but has around thirty stars of second and third magnitude and 70 of greater than sixth, including a number of binary or multiple stars. Among the stars which make up the constellation figure, only a few are named stars, the brightest is α Lupi, or Men, a blue giant. β Lupi has the name Ke Kouan. Most of the brightest stars in Lupus are massive members of the nearest OB association: Scorpius-Centaurus.

Towards the north of the constellation are globular clusters NGC 5824 and NGC 5986, and close by the dark nebula B 228. Two open clusters are to the south of the constellation, NGC 5822 and NGC 5749. On the western border are two spiral galaxies and the Wolf-Rayet planetary nebula IC 4406, containing some of the hottest stars in existence. Another planetary nebula, NGC 5882, is towards the centre of the constellation. The transiting exoplanet Lupus-TR-3b lies in this constellation.

The constellation has no clear mythology, but is sometimes associated with the tale of King Lycaon. Although known from ancient times no particular animal was associated with it until the Latin translation of Ptolemy's work identified it with the wolf. It was not separated from Centaurus until Hipparchus of Bithynia named it Therion (meaning beast) in the 200s BC. Prior to its separation it was considered an asterism of Centaurus, and was considered to have been an arbitrary animal, killed, or about to be killed, on behalf of, or for, Centaurus. As such, together with other constellations in the Zodiac sign of Virgo (specifically, Sagitta, and Centaurus) it may have formed the basis of the tale of the Erymanthian Boar, one of The Twelve Labours of Heracles.

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