Messier 15 (also M15, NGC 7078, Struve 9 and GCL 120) is a magnitude +6.2 globular star cluster located 33,600 light-years away in the constellation Pegasus. The cluster is filled with old orange and yellow giants stars. Pease 1 is a planetary nebula located within the globular cluster.
The cluster was discovered by Italian-born astronomer Jean-Dominique Maraldi using a 12.7 cm (5-inch) 10.4 metre (34-foot) focal length Campani refracting telescope at the Paris Observatory on the 7th September 1746. The cluster was serendipitously discovered by Maraldi while observing Comet De Chéseaux with Jacques Cassini. The cluster was recorded by French astronomer Charles Messier using a 8.38 cm (3.3-inch) refracting telescope at the Hôtel de Cluny, in Paris, France in June 1764.
Right Ascension 21h 29m 58.33s, Declination +12° 10' 01.2"
At an estimated 12.0 billion years old, it is one of the oldest known globular clusters. Read more