Astronomy thesaurus

Abbrev	Name	Description
Con	Constellation	A Constellation is any one of the 88 areas into which the sky - or the celestial sphere - is divided. The term is also often used, incorrectly, to denote a group of stars visibly related to each other in a particular configuration or pattern. Examples of constellations are: Ursa Major (En: Great Bear), Orion and Leo.
M	Messier	Charles Messier published a catalog of 45 deep sky objects (Nebulae and Clusters). In 1781 the catloque has grown to 110 objects.
NGC	New General Cataloque	The New General Catalogue (NGC) is the most well-known catalogue of deep sky objects in amateur astronomy. It contains nearly 8,000 objects, known as the NGC objects. List of NGC Objects.
RA	Right ascension Greek: α	Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination. RA can be used to determine a star's location and to determine how long it will take for a star to reach a certain point in the sky. That certain point is the Meridian.