Description | Images |
Object name: NGC6991Designation(s): NGC6991, IC5076, IC 5076 is a reflection nebula seen against a large open cluster known as NGC 6991. The problem is there are two clusters with the NGC 6991 designation. Both are in my image. William Herschel described the cluster as the one in the center around which is the reflection nebula IC 5076 which is illuminated by the 6th magnitude star. I can't determine if that star is related to the cluster or not. John Herschel, William's son described a cluster seen to the lower right of the nebula. Yet others consider NGC 6991 to not only be both clusters but a much larger region of bright stars centered up and to the right of the nebula. WEBDA agrees to the latter while Seligman says it is the cluster just to the southwest of the nebula. And you thought astronomy was an exact science. In any case, my target is the reflection nebula. That object's location isn't up for debate. The nebula was not noted by either Herschel. I've seen no common name for this nebula. I could find only a very few images of it on the net. It is located in Cygnus, a constellation that is full of emission nebula but only a very few reflection nebulae. |