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Edge-on
Spiral Galaxy Mean Surface Br. 23.5 Mag/arc-secē Minimum requirements to detect: 12-inch? under dark skies |
UGC 7321 is an example of a superthin galaxy. These are low surface brightness spiral galaxies seen nearly edge-on. They are gas rich with very flattened stellar disks. Little or no nuclear bulge is seen. These features give such galaxies a unique appearance in the eyepiece; that of a thin streak of light. UGC 7321 is one of the more extreme galaxies of this class. Almost unknown except to a very few observers, this galaxy is a real treat. Unfortunately it is too faint to be easily observed in smaller instruments.
In my 18-inch f/4.5 at 94x UGC 7321 appeared as a very faint, very thin streak. It was faint enough that it was only just visible with direct vision. It appears as a hazy line of light, ever so slightly wider near the middle. I could easily imagine that I was seeing a very faint meteor train that has almost faded into the night. Because it is so diffuse, with no appreciable brightening toward the center, there is something almost ghostly about it. At 258x the galaxy appeared much larger, but was not any more easily seen.
The field in an 12-inch LX200 at 140x. North is down and east is to the right.
| Millennium Star Atlas Vol II Chart 678 Sky Atlas 2000 Chart 7 Uranometria 2000 Vol I Chart 148 Uranometria 2nd Ed. Chart 72 Herald-Bobroff Astroatlas B-09 C-30 |
