Sketch of NGC 891
Observation Notes:
This large, edge-on galaxy is no friend of man-made light sources. It was not difficult to find, but was still rather subtle from my back yard. It appeared as a slender, soft brightening of the sky and shared space with one rather distracting star. This star was located on the west side of the north spine of the galaxy. The glow from the star overpowered the galaxy on the north side enough to make it look lopsided at a glance--like the south spine was bulkier. Perhaps when observing from a darker site, the galaxy's luminosity would be able to hold its own against the background sky glow and that star would not seem to interfere as much. Another faint star marked the southwest tip of the galaxy's profile.
I analyzed the field for some time, to see if I could detect the central dust lane, but only got a couple fleeting hints of it. I wasn't confident enough in those glimpses to record it in the sketch. Once again, a darker sky would probably help in that effort. The galaxy appeared to be about 15 x 2 arc minutes in size and aligned at a PA of about 40 degrees. That doesn't match well with the published value of 22 degrees--it looks like I marked my west point a bit further clockwise than it actually was.
Object Information:
NGC 891was discovered by Karoline Lucretia Herschel in 1783 and is a member of the NGC 1023 group. It is also cataloged as: UGC 1831, MCG+07-05-046, H V-19, h 218, GC 527, CGCG 538.052, PGC 9031
| Subject | NGC 891 |
| Classification* | Galaxy (Sb) |
| Position* | Andromeda [RA: 02:22:33.5 / Dec: +42:21:03] |
| Size* | 13.5' x 2.5' (PA 22°) |
| Brightness* | 10.0 vMag (10.6 bMag) |
| Date/Time | NOV 30, 2008 - 10:30 PM MST (DEC 1, 2008 - 05:30 UT) |
| Observing Loc. | Flagstaff, Arizona, USA - Home |
| Instrument | Orion SkyQuest XT8 (203 mm dia./1200 mm F/L) |
| Eyepieces/Mag. | Pentax XW 10 (120X) |
| Conditions | Clear, cool, breezy |
| Seeing | 5/10 Pickering |
| Transparency | ~ Mag 6.0 NELM |
| *References | NGCIC.org |
Great sketch Jeremy. I think you've done a superb job of conveying just how subtle this galaxy is. I've tried locating NGC 891 a few times and it completely eluded me on all occasions.
Hi Ewan, thanks very much for the comment. I hope you get an opportunity to track it down under more transparent conditions. It was definitely one of those objects that would completely disappear given the slightest opportunity.
Eric Graff sent me a message about this observation last night. He noted that from a very dark sky, he was able to observe the bisecting dust lane with his 6 inch Parks Newtonian. My conditions just wouldn't allow a verifiable sighting of it. It's one of the sacrifices I'm making with my observing these days. Losing at least a magnitude to observe from my back yard vs. not getting out at all means I'm not seeing as much detail as I could. But NGC 891 is on my re-observe-from-a-true-dark-sky list...along with a bunch of other extended objects. :)
Ewan, what kind of sky conditions do you have access to when doing deep sky observing?
Jeremy
I'm observing from an urban back yard. The town of Falkirk near where I live sits just outside the Grangemouth oil refinery which throws a mass of light pollution up into the sky.
Visually I'm can get down to about magnitude 5 and through my 25x100 bins I can get down to stars around magnitude 9/10. A dark sky site would definitely be preferable.