M71

From South Dublin Astronomical Society

M71
Type	Globular cluster
NGC	NGC 6838
Constellation	Sagitta
Right Ascension	19h 53.8m
Declination	+18° 47'
Magnitude	8.3
Size	7 arc min.
Image:M71 messier image.jpg

For many years, M71 in Sagitta was an object that defied classification though it was believed to be a very compact and rich open cluster. Now, the general consensus is that it is a loose globular cluster. What makes it particularly difficult to pigeon-hole this object is that many sources differ in their surveys of M71. The most recent estimate is that it lies 13, 000 light years away which would make it extremely remote if it was an open cluster. As a globular, analysis of it’s stars shows they differ in a number of ways from those making up the general population of such a class of object. M71 is found in the same field of view as Gamma Sagittae. Look about 1¼° to the southwest of the star and you’ll see the cluster as a broad glow of moderate brightness elongated in a north-south direction. A small triangle of suns lie just to the west with another brighter star capping the trio, making for an attractive field in this rich section of the Milky Way.