Astronomers from the European Space Observatory at La Silla Observatory in Chile have recently unearthed a new discovery, a peculiar dark nebula located some 6,000 light-years distant in the Sagittarius Star Cloud.
The constellation the cloud can be found in, Sagittarius (or The Archer), is known for its plethora of star fields that litter the overall area of the Large Sagittarius star Cloud. The huge concentration of stars from the NGC 6520 cluster (the large, pale blue stars to the left of Barnard 86 and centered), densely scattered about are helpful in emphasizing the blackness of bok globule (cold, dense, dark clouds of dust) like Barnard 86, which can be seen at the center of the newly released image.
Often, these busy cosmic regions, which are thought to be stellar nurseries, are completely opaque to visible light, as the dust contained within the nebulae absorbs the light from the background stars, making them difficult to study at optical wavelengths.
See a larger version of this image here.