Wrote this a while ago.
"The wonderful open cluster M11 is Scutum’s best deep sky object and one of the jewels of the heavens. Discovered by Gottfried Kirch in 1681, this group is easily seen in the smallest of apertures, lying on the northern edge of the Scutum Starcloud. Turning a telescope onto M11 will show hundreds of white stars, not unlike a globular cluster in form. Higher power will allow you to descend into the core and an intriguing sight is a black starless patch west of the central mass of stars. A 20cm aperture will show around 400 stars of 11th magnitude and fainter, including one of 8th magnitude near the central region whilst a large mirror will show at least that many again.
Admiral Smyth thought M11 resembled a "flight of wild ducks" hence its common name "The Wild Duck Cluster". The density of stars in this region is so great that stars near the centre are possibly only 1 light year apart. These are very luminous stars, as our Sun, if placed within this cluster, would shine at around 15th magnitude. The total luminosity of M11 is about 10 000 times that of our Sun and the combined mass around 2900 times. Trumpler, a specialist investigator of clusters wrote that"...at the centre of M11 theobserver would find about40 stars with parallaxes of 2" or more and which would appear from 3 to 50 times as brilliant as Sirius shines in our sky".
There are many dark obscuring nebulae scattered about this region, the most obvious being B119a and B111. Look north of M11 for two black spots shaped like kidneys and almost in contact. Separating these two fine dark clouds are a number of 8 th to 10 th magnitude stars.
Another impressive and extended cloud lies around 0.5º southeast of M11. Barnard 114-118 blends together as a long inky black lane contrasting brilliantly with the surrounding bright starfield. Barnard 103 is a 1º wide cloud lying midway along a line joining alpha and beta ."