M67

From South Dublin Astronomical Society

M67
Type	Open Cluster
NGC	NGC 2682
Constellation	Cancer
Right Ascension	8h 51.4m
Declination	+11° 49'
Magnitude	6.1
Size	30 arc min.
Image:M67 messier image.jpg

Within the same binocular field as Alpha Cancri (Acubens) is the ancient galactic cluster M67. The cluster is seen as an elongated mottled haze about two degrees west of the star. Larger glasses let you glimpse a sprinkling of the brighter 9th magnitude members of this association while an unrelated 8th magnitude sun lies just outside its northern edge. M67 is considered one of the oldest galactic clusters known with an estimated age of four billion years. This poses the question as to how its stars have remained gravitationally-bound over such a long period of time. Most open clusters are disrupted after a few hundred million years following encounters with other clusters or by successive passages through giant interstellar gas clouds during their orbit around the galaxy. The key to the survival of M67 however lies in its great distance (1,500 light years) above the plane of the Milky Way.