[LVAS] NGC-891 Reference Information

[roger ivester]

All,
 
Some information that may be of value in your quest for the Observers Challenge for November, which is the faint galaxy NGC-891 located in the constellation Andromeda.
 
Rob has already noted that this galaxy may be a more difficult object to observe. I certainly agree. Rob, also reported that Skiff and Lunginbuhl could see it with a 60 mm refractor. This has always been fascinating to me as I have been unable to see this very LSB galaxy using my 4-inch refractor from my backyard with moderate light pollution. This comparative would indicate the absolute importance of a dark sky, an excellent location and a skilled observer.  
 

It can also be difficult when using my 10-inch reflector from the backyard if conditions and transparency are not excellent. On those nights of lesser conditions it is barely discernable at all. 

 

I am hopeful that I can observe this galaxy from a dark site with my 4-inch. If I am successful my plans are to reduce the effective aperture of the 4-inch to that of a 60 mm, using a fabricated stop down aperture mask. It would be most interesting if I could follow Skiff and Luginbuhl and glimpse this galaxy with such a small aperture. 

 

Good luck to all with your observation of this galaxy. It is indeed a fabulous object and I'm sure it will prove to be an excellent selection for careful study.

 

Best regards, Roger 
 
 
NGC-891 References:  
 
The Amateur Astronomer's Field Guide to Deep-Sky Observing by Tom Lorenzin: 
11.5M; 12' x 1' extent; edge-on spiral with equatorial dust lane; good supernova prospect 20' NW of bright star (6.7M) SAO 38002.
 
Celestial Harvest by James Mullaney: Not an easy object in small telescopes. Tough in 8-inch under light polluted skies - needs at least a 12 to 14-inch and a dark night to really appreciate. One of the legendary faint galaxies. The dark lane bisecting the galaxy has been glimpsed visually in large scopes with difficulty.
 
Galaxies and The Universe...An observing guide from Deep-sky magazine: by David Eicher, Editor: NGC-891 in Andromeda is another well-known Sb galaxy. After NGC-4565 in Coma Berenices, this galaxy is the best galaxy in which to observe an equatorial dust lane. It's surface brightness is fairly low, so dark skies are required for a good view. 
 
Observing The Constellations by John Sanford: NGC-891 is a relatively nearby spiral galaxy seen edge-on. In an 8-inch or larger aperture instrument it is seen as a large 12 arc minute long streak with a dark lane particularly prominent with greater telescopic apertures. It is not a bright object (12th magnitude) and therefore requires a moonless night and a pure sky to be seen well.
 
The Herschel Objects by the Ancient City Astronomy Club, published by the Astronomical League: Magnitude 11.5, spiral galaxy in Andromeda, 11.8' x 1.1' in size, located 4° east of Gamma 1 & 2 Andromeda. Extremely elongated, edge-on bright nucleus fading outwards. (6-inch Cass.)
 
Burnham's Celestial Handbook by Robert Burnham, Jr. : The galaxy is not an easy object in the small telescope since the surface brightness is quite low, but on a clear night it may be detected with an aperture of 5 or 6-inches.      
  
Observing Handbook and Catalogue of Deep-Sky Objects by Christian Luginbuhl and Brian Skiff: A difficult object in 6 cm, this edge-on spiral is visible as a tiny streak of low surface brightness. 25 cm (10-inch) shows it faintly, about 10' x 1' in extent with a broad and moderately brighter core. The galaxy appears very faint and thin in 30 cm (12-inch) in pa 25°. The broad weak central brightening is about 4' x 2' with two brighter condensations, the brighter one located on the E side of the core. The halo is most extensive to the SSW, extending all the way to a mag. 13 star; before reaching this star, there is a small, slightly brighter patch in the halo 30" (arc seconds) across. A mag. 12.5 star lies just N of the core, and a mag. 14.5 pair (30";85° PA) is 1'.5 SSW of the core.  

 

 


  
 
 
 
 
   
 
 
 


 
 
 
 
 
 
 
 
 

 
    The moon and stars to govern the night.....   Psalm 136:9





 		 	   		  
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