DSO of the Month :
Messier 11
AKA: Wild Duck Cluster; NGC 6705; Collinder 391
Position: 18h 51.1m 00s, −06° 16′ 00″
18h 51.1m 00s, −06° 16′ 00″
18 hr 51 min 00 sec -06 degrees 16 min 00 sec
Due south at 22.15 (BST) on 15 August 2022
Messier 11
Image by HAS member Martin Gill (used with permission)
Whereas M54 (DSO of the Month for July 2022) was very low in the sky, M11 is much better placed. It is in fact almost directly above M54 by about 23 degrees. At magnitude 5.8 it is a fairly bright open cluster and in a very dark area (i.e. not Havering), it should be visible to the naked eye. It is also fairly easily found. Starting at magnitude 3.4 Lambda Aquilae, the tail of the Eagle constellation (see the Double Star for this month), drop down to nearby 12 Aquilae (mag. 4.0) and then then downwards and to the right (east) to Eta Scuti (mag. 4.8) and then carry out in the same direction (towards Alpha Scuti, mag. 3.9) to reach M11. It is compact cluster which in the telescope or binoculars looks like a flight of three ducks or a single duck, depending how you see it. This anatine feature is not obvious in images! 7,638 light years away from us, M11 is about 250 million years old, so fairly young but older than the Pleiades. For its age this cluster is surprisingly metals-rich (metals in astronomy are any elements apart from hydrogen and helium), which may be a result of a nearby supernova when the cluster was being formed. Although it is a Messier object, the Wild Duck Cluster was first observed by the German astronomer Gottfried Kirsch in 1681. The stars in M11 were first resolved by William Derham, Rector of Upminster, around 1730.
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