The Inkspot Nebula or Barnard 86
Image details: Scope AP 5” Refractor.
Exposure: 80 minutes
The Inkspot nebula (B86) is a tiny dark cloud in the very rich Sagittarius star cloud which is a very dense area of the Milky Way spotted with numerous stars. The nebula almost completely obscures the background stars of Milky Way (5 out of 6 in opacity scale) - giving an impression of a spilled spot of black ink. The nebula is adjacent to a small and rich open cluster of similar size (NGC 6520) - which can appear like it was torn out of the milky way, leaving a "hole" behind.
Also known as Barnard 86 it was discovered by Edward Emerson Barnard in 1919. Even the name of the nebula is originating from Barnard, because he described it as "a drop of ink on the luminous sky". As it can be observed in the picture: this region of the sky is full of stars, every single bright dot in the picture is a star, there is one for almost each pixels of the image.
Compact and dense interstellar clouds, like Barnard 86 are also called Bok globules, and often new stars are being formed inside them. Very likely it is the case with Barnard 86 as well, and a new generation of stars are being born from the dense cloud. Next to the right hand side of Ink Spot nebula a couple of bright blue stars can be observed, members of the open cluster called NGC 6520. The age of them are estimated about 60-150 million years, which is very young in astronomical terms (the age of our Sun is 4.6 billion years). Since both the cluster and the nebula are in the same distance from us, about 6-7000 light-years, suggesting that the stars of the cluster were formed of the same molecular cloud which the Ink Spot nebula is a remainder of.
To the right of the Inkspot Nebula you can see Djorgovski 2 an ancient Globular Cluster of stars embedded deep within the Milky Way. It was discovered by Stanislav George Djorgovski American astrophysicist in 1978. Located in the galactic bulge, one of the closest GCs to the center of the Milky Way. Given their location, such clusters as Djorgovski 2 are among the oldest known to date, some estimated put it as 12.7 billion years old. The cluster has a relatively eccentric orbit, with a radial distance between 330 and 8,150 light years from the center of the Milky Way.
To the left of the Inkspot Nebular is another globular cluster called NGC 6540. Its apparent magnitude is 9.3 and its diameter is about 9.5 arcminutes, with 12 faint stars visible. It is about 17,000 light years away from Earth and was discovered by Wilhelm Herschel on May 24, 1784 with an 18.7-inch mirror telescope, who described the cluster as "pretty faint, not large, crookedly extended, easily resolvable".