Constellations de la Boussole et du Grand Chien - Constellations of Pyxis and Canis Major...

Constellations de la Boussole et du Grand Chien - Constellations of Pyxis and Canis Major - Constellation de la Boussole, pres de l'horizon, et constellation du Grand Chien avec la brillante etoile Sirius.En haut, la constellation du Petit Chien avec l'etoile Procyon. Pyxis, the Mariner's Compass was originally Pyxis Nauticus and refers to the magnetic compass. It is a small, insignificant arrangement of faint stars surrounded by much more eyecatching patterns of stars. Pyxis was once part of the very large constellation Argo Navis, the ship Argo, which carried Jason and the Argonauts. Argo Navis is now obsolete, but it was listed in Ptolemy's star catalogue, the Almagest. When the constellation boundaries were defined by the International Astronomical Union in the 1930s it was the only one of Ptolemy's 48 constellations that was not accepted. Instead, it was divided into the four constellations introduced by the French cleric and astronomer Nicolas de Lacaille in the 1750s: Carina, the keel, Puppis the stern, Vela the sails, and Pyxis. La Caille originally called this part of Argo Navis Malus, the Mast, which is rather more appropriate since the ancient Greeks did not use the magnetic compass, and such compasses are not usually used on a ship's mast. However, alpha Pixidis, is sometimed known by its Arabic name Al Sumut, meaning ""the way"". This word is the origin of azimuth, a directional coordinate on the horizon