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There was much discussion as to whether M71 was a globular cluster or an open cluster. It is a bit too open to be a globular but a bit too compact to be an open, so it is now referred to as a loose, globular cluster. It was first observed by Loys de Cheseaux in 1745-6 and catalogued by Messier as M71 in 1780. It is 13,000 light-years away within the Milky Way galaxy and so there are many stars in the foreground and background that are unrelated to the cluster, making it difficult to tell where the cluster starts and finishes. The main part appears to subtend an angle of 5-6 arc-minutes which corresponds to about 27 light years. | ||
| Date and Time | 8th July 2007 00:35 UT | Camera | Atik ATK1 HS | Telescope | LX200 with 0.33 focal reducer (focal length 800 mm) | Capture | K3CCDTools. High gamma, exposure 5 sec, 91% gain, 72 frames | Processing | K3CCDTools. 44 frames stacked, histogram 0-180, unsharp mask 3,0,400 |
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