| Diffuse
Nebula with Open Cluster
aka IC 1590, Collinder 8, OCL 313 RA: 00h52m50.1s Dec: +56°37'17" (Cassiopeia) Integrated Visual Magnitude: 7.4 Angular Diameter: 4.0' Minimum requirements to detect: 6-inch under dark skies |
I've
heard this region referred to as the "Pac Man Nebula." To me, it
looks like a large, diffuse "P". There is a lot here to see.
The nebula itself is visible as a faint haze, cut by very distinct dark
lanes of dust. Within the nebula lies the open cluster IC 1590, a
very young group of stars that formed recently from the gas and dust complex.
Within the nebula lie several dark Bok globules and the cluster is highlighted
by the nice double star HD 5005.
The nebula is pretty faint without a filter, but with an OIII in place it stands out quite well. In my 18-inch f/4.5 at 94x the glow of the nebula was easily visible, although I would not claim it was obvious. It appeared as a slight, irregularly shaped haze with many stars embedded in it. The H-Beta filter helped some, but it was the OIII filter that really brought it out. At 250x without the filter the contrast was very much improved. With the filter in place this gave the best view. The nebula filled the field of view, spilling over in several directions. I identified at least four major parts, apparently separated by dark lanes.
The main pair of HD 5005 consists of a massive O star that shines at magnitude 7.8 and a 9th magnitude companion some 3.9" away. HD 5005 is the bright blue star in the image on the right. This hot, bright, primary star produces much of the radiation required to "light up" the gas in the nebula.
The field in an 6-inch f/8 at 50x. North is down and east is to the right.
| Millennium
Star Atlas Vol I Chart 65
Sky Atlas 2000 Chart 1 Uranometria 2000 Vol I Chart 36 Herald-Bobroff Astroatlas B-05 C-04 |
