Compiled by:
Glenn Chaple
Introduction
NGC 891 – Spiral Galaxy Cluster in Andromeda (Magnitude 9.9, Size 12’ X 2’)
If you’re a fan of TV sci-fi shows and are old enough, the accompanying image of the edge-on spiral galaxy NGC 891 taken by astroimager Mario Motta should look oddly familiar. It appeared, along with images of other galaxies, during the closing credits of the mid-1960s sci-fi anthology "Outer Limits."
Typical of edge-on spirals, NGC 891 displays a luminous spindle shape bisected by a dark lane. This lane, created by dust clouds that inhabit the spiral arms, obscures the galaxy’s bright nucleus. As a result, NGC 891 is much darker than its listed magnitude of 9.9 might indicate. Although glimpsed with difficulty with apertures as small as 4 inches, this low surface brightness galaxy more realistically requires an aperture of 8 to 10 inches under a dark sky environment.
To find NGC 891, owners of GoTo telescopes need only enter its 2000.0 coordinates RA 2h22m33s and DEC +42o20’53” and press the button on the control paddle. I recommend, however, that you eschew the electronics and “go to” NGC 891 via the star-hop method. The reason? Your starting point is gamma (γ) Andromedae (Almach), 3 ½ degrees due west. Mirach is one of the finest double stars in the night sky, a dazzling amber and blue pair whose magnitude 2.3 and 5.0 components are 9.5 arc-seconds apart. What a great way to begin your journey to NGC 891!
NGC 891 was discovered by (who else?) William Herschel on 6 October 1784 with an 18.7 inch reflecting telescope. He described it as “Considerably bright, much extended above 15' 3' broad, a black division 3 or 4' long in the middle.”
Most references assign a distance to NGC 891 of 30 million light years. Its apparent 12 arc-minute breadth translates to an actual size of 100,000 to 120,000 light years.
Here are your NGC 891 challenges: 1. Can you behold the beauty of the topaz and sapphire gem set Almach without being moved to tears? (OK, maybe hyperbole on my part, but this colorful pair is a stunning can’t miss sight.) 2. Can you glimpse NGC 891 with a telescope aperture less than 8 inches? 3. What is the smallest aperture that will capture the galaxy’s dust lane?
NGC 891 Finder Chart
(freestarcharts.com)
Reports
Mario Motta
NGC 891, 4 hours imaging with RGB and Lum filters, on my 32 inch scope and zwo 6200 camera.
Doug Paul
Canon 80D camera, 1200mm FL f8.0 lens, ISO 800 60x2m = 2hr, 1/3 scale, North up
David Giordano
14 hours of data collected over ten nights in December using Celestron Edge HD8 SCT and ASI 294MC Pro camera from my backyard in Carlisle, MA. Processed in PixInsight version 1.9.2 Lockhart.
Venu Venugopal
NGC891. It is taken with c11 edge, 30 sec subs, no guiding, 2 hours integration
Dave Wilbur
This is my image of NGC891. It was taken with a Seestar S50 (50mm, f5, 52 min exposure)
Rajeev Meharwal
Celestron EdgeHD 11, OSC (ToupTek ATR2600C), With OptoLong UV/IR Cut filter, 31 hours of integration time
