M18

From South Dublin Astronomical Society

M18
Type	Open cluster
NGC	NGC 6613
Constellation	Sagittarius
Right Ascension	18h 19.9m
Declination	-17° 08’
Magnitude	7.5
Size	9 arc min.
Image:M18 messier image.jpg

M18 is a lovely star cluster that lies in the same low power binocular field as the Swan Nebula and the Sagittarius Star Cloud — it’s set about midway between the two objects. This is a lovely juxtaposition of a star cluster, nebula, and Milky Way star cloud. A handful of bright stars is seen with the light from the rest of the members of the group combining as a faint background glow. To the west there is a particularly rich star field studded with a number of magnitude 6 suns. M18 is quite a young group with an estimated age of 32 million years. The cluster lies 4,900 light years away. Deep field photographs of the region reveal some wisps of gas that may be some material left over from the formation of the cluster’s stars.