BAS Observer March 2018

14 BAS OBSERVER Meridian constellations The Puppis constellation represents the stern of a ship – the poop deck. Puppis used to be part of the much larger constellation Argo Navis, which represented the ship on which Jason and the Argonauts sailed to get the Golden Fleece, before the constellation was divided into several smaller ones: Carina (the Keel), Vela (the Sails) and Puppis (the Stern). Argo Navis was first catalogued by the astronomer Ptolemy in the 2nd century. It was divided into the smaller constellations by Nicolas- Louis de Lacaille in 1752. Puppis is a relatively large constellation which contains many notable deep-sky features, including three Messier objects: the open clusters M46, M47 and M93. The Monoceros constellation lies in the northern sky, on the celestial equator. Its name means ‘the unicorn’ in Latin. Monoceros was introduced by the Dutch astronomer and cartographer Petrus Plancius from the observations of Dutch navigators in the 17th century. The constellation represents the mythical single-horned, horse-like creature. Monoceros is a relatively faint constellation; however, it also contains several interesting deep-sky objects: the open cluster Messier 50 (NGC 2323), the Rosette Nebula, the Christmas Tree Cluster, the Cone Nebula, and Hubble’s Variable Nebula. Puppis Not too far from the bright star Canopus is the Messier 46 open cluster. It is worth searching for, as it contains a beautiful little foreground planetary nebula. The nearby open cluster Messier 47 contains many much brighter stars than M46. Monoceros The stunning Rosette Nebula is located near the nose of the Unicorn, while the faint Cone Nebula and much brighter Christmas Tree open cluster are located near the base of the Unicorn’s horn. Puppis Monoceros