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auriga
scholastic sledgehammer
Reged: 03/02/06
Posts: 794
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Hi, all,
A few nights ago I tried for 891 in a mag 5 sky with a bit of haze perhaps but no clouds. The Milky Way was dimly visible. I found that NGC 891 was visible as a huge long shadow of almost nothing. It intersected horizontally a vertical line of three stars. I used a 16 inch Dob and an 8 Ethos with Paracorr, giving about 225x. 891 ran across most of the field of view. The view was confirmed by another observer, my friend Mathias, or I would have doubted that I really saw it.
I have seen photos and so I know it is quite beautiful but I find it surpringly fainta especially since I used a large scope..
Has anyone else reported difficulty seeing this huge faint galaxy?
Bill
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8273
Loc: Beatrice, Nebraska
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Quote:
Hi, all,
A few nights ago I tried for 891 in a mag 5 sky with a bit of haze perhaps but no clouds. The Milky Way was dimly visible. I found that NGC 891 was visible as a huge long shadow of almost nothing. It intersected horizontally a vertical line of three stars. I used a 16 inch Dob and an 8 Ethos with Paracorr, giving about 225x. 891 ran across most of the field of view. The view was confirmed by another observer, my friend Mathias, or I would have doubted that I really saw it.
I have seen photos and so I know it is quite beautiful but I find it surpringly fainta especially since I used a large scope..
Has anyone else reported difficulty seeing this huge faint galaxy?
Bill
I don't usually have much trouble seeing it when it is nearly overhead from my dark sky site (ZLM 6.0 to 6.7) in my 9.25 inch f/10 SCT. It is quite faint with a very low surface brightness, but with averted vision, I can often see the famous long dark lane down the middle. From my home (ZLM 5.5), it is much harder, although it is still visible when I use my Lumicon Deep-sky filter and keep the power fairly low. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org
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Jeremy Perez
Carpal Tunnel
Reged: 08/12/04
Posts: 1930
Loc: Flagstaff, Arizona, USA
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Hi Bill,
These are my notes on NGC 891 using an 8 inch f/5.9 Dobsonian at 120X with a Pentax XW10 eyepiece under approx. Mag 6 skies with incidental, reflected light pollution bouncing off nearby houses:
Quote:
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.
And the sketch:
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Orion SVP 6LT (6" f/8 Newt) || Orion XT8 (8" f/5.9 Dob) || 15x70 Oberwerk Binoculars || Coronado PST
The Belt Of Venus || Sketch Gallery || Sketching Resources || Astro-Photo Gallery
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rocco13
Got Milk?
Reged: 07/29/06
Posts: 2643
Loc: Phoenix, Arizona
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This object, more than any other, has given me fits. According to the statistics, it should be visible in my scopes here at home on the edge of the 'burbs. But even the slightest amount of light pollution makes it invisible, in my experience. In dark skies, unless the transparency is really good, it is still 'ghostly' at best. Under good conditions, the dust lane was directly visible in my 15" dob, but other times it was only seen with averted vision.
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Rocco
Zhumell Z12
Super C8 (1984 vintage)
Celestron 102 f/5
and a cheap pair of binoculars
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Tony Flanders
Post Laureate
Reged: 05/18/06
Posts: 3457
Loc: Cambridge, MA, USA
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Good for you! Seeing NGC 891 in a mag-5 sky is no mean feat -- even through a 16-inch scope. This galaxy has quite low surface brightness. However, it's really quite glorious -- one of the best -- when viewed with averted vision from a dark site.
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Tony Flanders
First and foremost observing love: naked eye.
Second, binoculars.
Last but not least, telescopes.
And I sometimes dabble with cameras.
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Achernar
Postmaster
Reged: 02/25/06
Posts: 5024
Loc: Mobile, Alabama, USA
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This galaxy is a ghost because of it's light being spread over a large area. Large telescopes are not what's necessary to see NGC-891, it's dark and clear skies that are more important given that it can be seen with a 6-inch from a dark site. From the usual sites I have access to, NGC-891 is a difficult object for my 10-inch, but it's no where near as hard to see as the likes of NGC-147 and NGC-7640 in Andromeda, NGC-247 in Cetus or NGC-6822 in Sagittarius are. Generally speaking, if you can detect this galaxy, you have a pretty observing good site and sky conditions.
Taras
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15-inch F/4.5 Dob under construction
10-inch F/4.5 Discovery Dob
6-inch F/8 Homebuilt Dob
4 1/4-inch F/4 Homebuilt reflector
A whole bunch of eyepieces, filters and other accessories....
Two curious cats
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auriga
scholastic sledgehammer
Reged: 03/02/06
Posts: 794
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Quote:
This galaxy is a ghost because of it's light being spread over a large area. Large telescopes are not what's necessary to see NGC-891, it's dark and clear skies that are more important given that it can be seen with a 6-inch from a dark site. From the usual sites I have access to, NGC-891 is a difficult object for my 10-inch, but it's no where near as hard to see as the likes of NGC-147 and NGC-7640 in Andromeda, NGC-247 in Cetus or NGC-6822 in Sagittarius are. Generally speaking, if you can detect this galaxy, you have a pretty observing good site and sky conditions.
Taras
Thanks everyone for your observations and experiences with 891, and your excellent sketches, very helpful in putting my experience in perspective. What I saw is very similar to the sketches, which tempts me to try sketching myself, I like the results you have achieved.
NGC 404 by comparison was bright in the 16" which tells me again how different galaxies are from each other.
It occurs to me that 225x may have been too high a power for NGC 891. I had just been looking at MGC 404, which is so much brighter, at that power and I simply switched over to 891 without thinking too much about it.
In regard to NGC 6822, I have seen it fairly easily from a mag 7 site at the Shingletown Star Party (nowadays, the Golden State Star Party) in California, in a 16 inch. Since 6822 is said to be harder to see than NGC 891, this tells me again the value of really dark skies.
Bill
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Starman1
Vendor - Scope City
Reged: 06/24/03
Posts: 12220
Loc: Los Angeles
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Quote:
Quote:
This galaxy is a ghost because of it's light being spread over a large area. Large telescopes are not what's necessary to see NGC-891, it's dark and clear skies that are more important given that it can be seen with a 6-inch from a dark site. From the usual sites I have access to, NGC-891 is a difficult object for my 10-inch, but it's no where near as hard to see as the likes of NGC-147 and NGC-7640 in Andromeda, NGC-247 in Cetus or NGC-6822 in Sagittarius are. Generally speaking, if you can detect this galaxy, you have a pretty observing good site and sky conditions.
Taras
Thanks everyone for your observations and experiences with 891, and your excellent sketches, very helpful in putting my experience in perspective. What I saw is very similar to the sketches, which tempts me to try sketching myself, I like the results you have achieved.
NGC 404 by comparison was bright in the 16" which tells me again how different galaxies are from each other.
It occurs to me that 225x may have been too high a power for NGC 891. I had just been looking at MGC 404, which is so much brighter, at that power and I simply switched over to 891 without thinking too much about it.
In regard to NGC 6822, I have seen it fairly easily from a mag 7 site at the Shingletown Star Party (nowadays, the Golden State Star Party) in California, in a 16 inch. Since 6822 is said to be harder to see than NGC 891, this tells me again the value of really dark skies.
Bill
891 hard in a 16"? Oof! Bright skies. In dark skies it's visible in 3-4". And my 12.5" in dark skies not only shows the lane, but also a horde of knots along the body of the galaxy. What really sets 891 apart from a lot of other edge-ons is the rich Milky Way field it sits in.
Paradoxically, 6822 is easy in a 4" f/6 and hard in a 10" SCT. It is easiest with wide fields that show contrasts the best. I've heard of it being seen in 10x50 binoculars (I haven't tried), but a lot of observers have a hard time. I think the skies need to be dark, you need to use low powers, and you need to know what to expect. Once you see what it looks like, it'll be viewable in a much smaller aperture. That's a good rule for 891, too. I had to hunt for the Horsehead with my 12.5" when I first sought it out, and I was using an H-Beta filter. Now that I know both where it is and what to expect in terms of size and brightness, I see it instantly, even without a filter.
In a sense, each observer recapitulates the discovery of each DSOwhen viewing an object for the first time, when you think of it, and each of the objects we view was discovered with larger scopes in darker skies (that is, I realize, a generalization). The Veil nebula was once thought to be a large scope or photographic object, but has been seen with the naked eye plus O-III filter. It always takes a larger aperture to discover something than it does to see it later. Read some of the amazing posts of veteran observers who've traveled the world with 60-80mm refractors. Some of the objects observed are hard with 10"+!
When seeking fairly big objects, try not to exceed 10x/inch of aperture. Once you find the objects, try whatever power suits your fancy.
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Don Pensack
12.5" Truss Dob, 5" Maksutov, Fujinon Binos
Sustaining Lifetime IDA member
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Bill Weir
Pooh-Bah
Reged: 06/01/04
Posts: 1297
Loc: Metchosin (Victoria), Canada
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I think you hit the nail on the head with your decision on magnification, although it's not so much the mag but the FOV. I've found that with objects of low surface brightness, adding a little more space around the object helps them stand out.
From a site at 7000', and a SQM reading of 21.65 I've spotted this galaxy with my ED80.
Bill
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6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar ED II
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2008, 121.
So far in 2009, 92
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Cygnus_x1
Sketcher Extraordinaire
Reged: 11/17/04
Posts: 2385
Loc: 50N - too far north!
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Here's mine, from 2005, sorry about poor quality pic:
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Visual Deep Sky Observing - being rebuilt
Observing blog
My astronomy event photos on Flickr
12 inch Dob
8 inch Celestron C8 Newtonian
4 inch Meade SCT
8x42 Leica binoculars
Various TeleVue eyepieces
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azure1961p
professor emeritus
Reged: 01/17/09
Posts: 731
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Your experience is all about your skys. In 6V with my 8 its pretty close to the 8" sketch shown in this thread. Sorry to say no dustlane in 6v skys - maybe 6.5v?
Its a really nice galaxy - just very demanding of a decent sky. I personally wouldnt think about it in any scope in any sky brighter than 6v.
Pete
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Bret Ford
sage
Reged: 07/15/07
Posts: 206
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I observed this galaxy last night/this morning at the Peddler Hill site in the Sierra Nevadas. Skies were mag 6.3-6.5 over the course of my observing session (best SQM-LE reading was 21.7 - pretty dark!). In my 20" it was a well-defined vertical gash in the sky, split through the middle by a dark lane. I observed it with 17 and 13mm EPs. 891 is one of my favorites.
Bret
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Patricko
Carpal Tunnel
Reged: 01/30/07
Posts: 1532
Loc: SE New Mexico USA
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Here are my experiences w/ NGC 891 from my notes:
11/29/08 6-7PM LT Blue observing site
Conditions: clear, cold, sliver of Moon set below Venus & Jupiter. Seeing: 3/10 Transparency: 7/10
Instrument: C5
First Time: NGC 891- best view w/ generic 25mm symmetrical @ 63x. This galaxy is larger in area compared to NGC 1023 but dimmer. Averted vision clearly shown the DSO as an edge-on spiral; also extreme averted vision hinted at what appeared to be a band running horizontally through the galaxy. Not going to say for certain I saw this feature but it "felt" like it was there.
Then....
12/14/08 6-7PM LT Blue observing site
Conditions: very windy earlier today. At the time of observing it was mostly clear, no Moon, breeze from the North
Seeing: 4/10 Transparency: 8/10
Instrument: 60mm f/11.7 Towa refractor
NGC 891-seen w/ slight averted vision w/ 32mm symmetrical (22x) and a 19mm 65 degree AFOV eyepiece (37x). This is a fairly difficult galaxy in the 60mm. Perhaps higher power will help?
And...
12/5/08 5:30-7:30PM LT Blue observing site
Conditions: getting colder, near first quarter Moon high in West sky, mostly clear, light breeze.
Seeing: 4/10 Transparency: 6/10 Instrument: 60/700mm
NGC 891- this was a tough one tonight! Never did see it w/ direct vision, only averted vision w/ consentration. A 26mm symmetrical seemed to work the best tonight @ 27x. The Moon did not help!
Finally....
12/15/08 7-8PM LT Blue observing site
Seeing: 8/10 Transparency: 9/10 Instrument: 60/700mm
Conditions: clear, cold, light breeze, no Moon
NGC 891- tonight is the best view yet I have had in the 60mm. Used the 19mm for 37x. The galaxy wasn't even difficult. Held with direct vision for several seconds at a time.
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Clear skies,
Patrick
INTERNATIONAL DARK SKY ASSOCIATION
60MM TELESCOPE CLUB!
"You can always have better, but will you ever be happy with what you have?" - Me, myself, and I
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Jim Curry
sage
Reged: 10/29/07
Posts: 431
Loc: Maine
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Jeremy and Taras's sketches are similar to mine except the two foreground stars are much closer to the ends. I'm not seeing that longish extension of nebulosity.
Jim
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Vixen 140 refractor
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azure1961p
professor emeritus
Reged: 01/17/09
Posts: 731
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Quote:
Here are my experiences w/ NGC 891 from my notes:
11/29/08 6-7PM LT Blue observing site
Conditions: clear, cold, sliver of Moon set below Venus & Jupiter. Seeing: 3/10 Transparency: 7/10
Instrument: C5
First Time: NGC 891- best view w/ generic 25mm symmetrical @ 63x. This galaxy is larger in area compared to NGC 1023 but dimmer. Averted vision clearly shown the DSO as an edge-on spiral; also extreme averted vision hinted at what appeared to be a band running horizontally through the galaxy. Not going to say for certain I saw this feature but it "felt" like it was there.
Brother, you just beat my 8" view. Ive so wanted to see the
d@%$#d band and through 6-6.2v skys, no such luck. I love the way you listed your accounts of the object by the way.
I will say however, and though it was still fringey for you, it does raise my hopes a little that it could one day be something that i will have "felt". There are no new mexico skys in ct though. Some good can be had in pockets, but it aint where you're at.
I'd love to know what color my zone is.
Pete
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Patricko
Carpal Tunnel
Reged: 01/30/07
Posts: 1532
Loc: SE New Mexico USA
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Hi Pete, here is a good site to determine what zone you are observing in....
http://www.jshine.net/astronomy/dark_sky/
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Clear skies,
Patrick
INTERNATIONAL DARK SKY ASSOCIATION
60MM TELESCOPE CLUB!
"You can always have better, but will you ever be happy with what you have?" - Me, myself, and I
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azure1961p
professor emeritus
Reged: 01/17/09
Posts: 731
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Thanks for the link. I added my condo, though I doubt it'll stay if good observing sites are a condition. While it's no surprise to me, the condo is in general city light pollution, I have repeatedly seen 15V in the "peach zone". It's a curious rating system as some of the same areas under the same zone color vary pretty strong. The same can be said abotu the yellow areas. Colebrook CT is dynamite, but another dark site a club uses just aint Colebrook and resembles more of the "peach zone".
I think its a matter of sat resolution. There are good pockets within some of those generalized zones. But, alas, my home is red and there just simply is no denying it. My site in Sherman however is definately yellow.
IT's an interesting thing - tough to know where to define it. But it was fun to see it!!!!
Many thanks!
Pete
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John K
scholastic sledgehammer
Reged: 12/26/05
Posts: 797
Loc: Vernon BC Canada
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Here is my sketch of it from a dark site on Friday.
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RASC Member (Okanagan)
Home built 15"F5 Obsession clone
Bushnell 76mm Modified Dob (Little Richie)
Celestron Skymaster 15x70
Howie Glatter laser pointer/Blug
Astronomik filters OIII UHC
Televue Eyepieces 31mmNagler,32mmPL,15mmPL,13mm Ethos,11mm PL,2X Barlow
10mm Speers Waler
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kcolter
member
Reged: 06/04/03
Posts: 87
Loc: Missouri, USA
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I absolutely love NGC 891. It's my good fortune to have a really big Dob (40"f5) under pretty dark skies, NELM 6.1ish. It is quite a sight in that scope. But even in such large aperture, the view I see will vary from night to night with the transparency. When conditions are right I have uttered "be still my heart" when looking at NGC 891. I am greatly impressed by Bill Weir's detection of this galaxy in an 80mm scope, even in extremely dark skies. The other thing about NGC 891 that I am often reminded of when it returns each year is how big it is.
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8273
Loc: Beatrice, Nebraska
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Quote:
I think you hit the nail on the head with your decision on magnification, although it's not so much the mag but the FOV. I've found that with objects of low surface brightness, adding a little more space around the object helps them stand out.
From a site at 7000', and a SQM reading of 21.65 I've spotted this galaxy with my ED80.
Bill
Well, from a "low" altitude of about 1403 ft. elevation, I have seen NGC 891 (barely), in my cheap little 80mm f/5 "short tube" refractor. It wasn't much (and I was able to find it mainly because I knew precisely where it was), but it was there. I once used the 70mm opening on my variable aperture off-axis stop for my 10 inch Newtonian, and was still able to just barely make out the elongated form of the galaxy at 47x. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org
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