martini man
member
Reged: 12/07/06
Posts: 72
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Hello fellow CN'ers
Need a little help with the eagle nebula. I am using a 10" GSO dob. I have a 17mm Nagler T4 and an 11mm T6. What can I expect to see without use of a filter? Just the open cluster and some nebulosity? Should I increase the magnification? I have an UHC filter, should I use it? Or forget it and use my buddy's 20" Obsession?  I want to make sure my expectations are not too high.
Clear Skies - MM
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10" DSO Dob
30 mm GSO Superview
Rigel Quickfinder
Whats this EP with green print on it? Nagler something?
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tatarjj
Pooh-Bah
Reged: 04/20/04
Posts: 1312
Loc: Austin, TX
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Quote:
Hello fellow CN'ers
Need a little help with the eagle nebula. I am using a 10" GSO dob. I have a 17mm Nagler T4 and an 11mm T6. What can I expect to see without use of a filter? Just the open cluster and some nebulosity? Should I increase the magnification? I have an UHC filter, should I use it? Or forget it and use my buddy's 20" Obsession? I want to make sure my expectations are not too high.
Clear Skies - MM
Depends on how dark your skies are. With dark skies, a haze surrounding the open cluster is easily visible unfiltered. No reason to look at it unfiltered though, use the UHC. With the UHC, you'll first notice that there appears to be a prominent "bite" or indention on one side of the nebula. THIS IS NOT THE "PILLARS OF CREATION". Using higher power, look directly opposite where the bite is and you may be able to pick up the "Pillars of Creation".
The Eagle Nebula is considered by some observers to be uninteresting and fairly faint, but it is only faint when compared to its neighbors M8, M17, and to a much lesser extent, M20. All things considered, it is a very bright nebula. With large apertures, the Pillars of Creation become very easily visible making the nebula quite a bit more interesting. I don't know how easily you will or will not see them in your 10"- please report back on this 
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John T.
Austin, TX
25" f/4.2 Dob
18" Obsession #701
4" Stellar Vue Achromat
8X56 Binos
Edited by tatarjj (07/20/09 01:33 PM)
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Houdini
professor emeritus
Reged: 07/13/07
Posts: 579
Loc: Europe
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At a reasonably dark location and with your UHC filter you won't have too much difficulity in picking it up in your 10".
Robert
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16" f/4.9 motorized alt-az, 25" f/5 Dobson, 43" f/4 alt-az under construction
Mirror Edge Support Calculator
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martini man
member
Reged: 12/07/06
Posts: 72
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Tatarjj, thanks for the quick response. I will attempt this tonight and see what I can tease out. Regarding darkness, CSC tells me Im in an orange zone, on a good night I can see a faint Milky Way (this time of year) and all the little dipper stars direct vision. You recommend using higher power, so would that be 150X or higher?
Thanks again
Clear Skies - MM
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10" DSO Dob
30 mm GSO Superview
Rigel Quickfinder
Whats this EP with green print on it? Nagler something?
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proud uncle
Carpal Tunnel
Reged: 01/22/07
Posts: 1631
Loc: Central Texas
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I have not had success seeing any nebulosity. But, I have no filters or dark skies. The cluster is very nice. One interesting thing is whether viewing the cluster through the eyepiece or images of the nebula, I can easily see the Eagle shape.
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Kenneth
Zhumell 10" Dobsonian (f/4.9)
2" 32mm WA eyepiece
9mm, 12.5mm, and 20mm Plossls
9mm Enhanced WA
6mm TMB/BO Planetary
2" 2x ED Barlow
Nikon 10x50 binocular (6.5 deg FOV)
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AlanK
professor emeritus
Reged: 01/26/07
Posts: 521
Loc: Auckland, New Zealand
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How dark are your skies from Texas?
I've seen it before unfiltered with a 10" as a large faint haze around the cluster from the suburbs of my old town in the UK but that was 20 years ago.
The pillars are much more difficult but were seen not too long ago filtered with the 18".
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Clear skies!
18 inch f4.5 Obsession #1637
12 inch f5.4 reflector
Just another frozen astronomer
Kumeu Observatory
Auckland NZ
7,379 deep sky objects incl 4,724 ngcs
Who dares - observes!
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blb
professor emeritus
Reged: 11/25/05
Posts: 510
Loc: Piedmont NC
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Three years ago while attending the Mid-Atlantic Star Party I saw the Eagle Nebula in my C11 unfiltered. It was not all that bright because it more than filled my field of view. What stands out in my memory is that I could see the Pillars easily and was so caught up in looking at them that I did not think to try and see how large the nebula was and how obvious the edge of it was. Anyway the nebula was obvious in the field of view.
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C-11, C-6, XT10i Dob, ETX125PE, TV102, & AT66
Edited by blb (07/21/09 02:09 AM)
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AlanK
professor emeritus
Reged: 01/26/07
Posts: 521
Loc: Auckland, New Zealand
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How dark were the skies there? Was the dark V shaped rift really evident?
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Clear skies!
18 inch f4.5 Obsession #1637
12 inch f5.4 reflector
Just another frozen astronomer
Kumeu Observatory
Auckland NZ
7,379 deep sky objects incl 4,724 ngcs
Who dares - observes!
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Scott K
Carpal Tunnel
Reged: 09/13/07
Posts: 1532
Loc: Dallas, TX & Eufaula, OK
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I don't have any trouble seeing the nebulosity from a dark site in a 12" scope. (For that matter, the nebulosity is fairly evident with an 8", if I recall correctly, especially with a filter.) I honestly never saw the pillars clearly until I looked at them with a 20". I think AlanK's advice is excellent - I noticed the dark V shaped rift first too. (In my 20", the V shaped rift is obvious.)
On a particularly transparent night (my SQM reading was 20.9-21) the nebulosity and rift were apparent without a filter. I maybe caught a glimpse of the pillars with averted vision. With a filter, it was pretty obvious.
I tried again a couple of nights later, on a less transparent night. (Still pretty dark though for here, SQM 20.77) I could still makeout the pillars with the filter, but it was definitely more difficult.
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proud uncle
Carpal Tunnel
Reged: 01/22/07
Posts: 1631
Loc: Central Texas
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Quote:
How dark are your skies from Texas?
Orange Skies. Last week (Friday night) I easily saw, though faint, the nebulosity in M8 and M20 including the dark dust lanes. I always easily see the brighter part of M17 (the Swan). One of these first clear nights I will try again for M16.
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Kenneth
Zhumell 10" Dobsonian (f/4.9)
2" 32mm WA eyepiece
9mm, 12.5mm, and 20mm Plossls
9mm Enhanced WA
6mm TMB/BO Planetary
2" 2x ED Barlow
Nikon 10x50 binocular (6.5 deg FOV)
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martini man
member
Reged: 12/07/06
Posts: 72
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Reporting Back - tried again last night still could not see the 'eagle' or pillars. I did note nebulosity in the area of the cluster, I noted a 'bite' but that was about it. I'm not giving up though, next clear night I'm trying again. I will look for the notch next time.
Clear Skies - MM
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10" DSO Dob
30 mm GSO Superview
Rigel Quickfinder
Whats this EP with green print on it? Nagler something?
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PeterSurma
super member
Reged: 08/24/06
Posts: 127
Loc: Heidelberg, Germany
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Hi,
if you cannot see the nebula, you should - of course - not try the pillars, because they are DARK structures in front of the nebula (you need the nebula to give you the contrast to the dark parts). They are pretty tough to spot, even with solid observational experience. Very good skies and 16"+ class scopes are needed I'd say. I've seen them once reasonably well with my 20" f/4 under a 21.4mag/sas sky. But they are far from 'easy' !
The nebula as such is not hard to get. Make sure to use line filters (rather use UHC, but OIII is OK too, just darker) to enhance contrast near the horizon or with LP.
Good luck !
Peter
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Peter
Web: http://www.eyes4skies.de/home_EnglishVersion.htm
Scopes: From 3inch photographic APO to 20inch f/4 Dob
Edited by PeterSurma (07/22/09 04:53 AM)
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AlanK
professor emeritus
Reged: 01/26/07
Posts: 521
Loc: Auckland, New Zealand
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Quote:
Hi,
if you cannot see the nebula, you should - of course - not try the pillars, because they are DARK structures in front of the nebula (you need the nebula to give you the contrast to the dark parts). They are pretty tough to spot, even with solid observational experience. Very good skies and 16"+ class scopes are needed I'd say. I've seen them once reasonably well with my 20" f/4 under a 21.4mag/sas sky. But they are far from 'easy' !
The nebula as such is not hard to get. Make sure to use line filters (rather use UHC, but OIII is OK too, just darker) to enhance contrast near the horizon or with LP.
Good luck !
Peter
Very good advice  although I'd also add that if the nebula is visible then the dark V shaped bay (not to be confused with the pillars!) should also be visible protruding in from the northern edge.
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Clear skies!
18 inch f4.5 Obsession #1637
12 inch f5.4 reflector
Just another frozen astronomer
Kumeu Observatory
Auckland NZ
7,379 deep sky objects incl 4,724 ngcs
Who dares - observes!
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martini man
member
Reged: 12/07/06
Posts: 72
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Thanks again for all the help. Just to verify, I suppose that all the photos of M 16 are oriented with N to the top. If that's the case, then I need to keep in mind that my view will be 'upside down'?
Clear Skies - MM
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10" DSO Dob
30 mm GSO Superview
Rigel Quickfinder
Whats this EP with green print on it? Nagler something?
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4330
Loc: Ireland
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From exceptionally dark but only moderately transparent skies I found the nebula easy unfiltered*, although with only the barest hints of the dark V or the pillars. The UHC improved things considerably, making both more readily detectable (although still far from obvious).
However, I didn't find the V that much more noticable than the pillars themselves (the V is larger, but less "dark").
10" DK @ 100 and 180X. NELM 7, SQM 21.6, 10,000' el.
Cheers,
-- Jeff.
* Make sure your field is big enough -- with the nebula filling the field of view it's pretty hard to make out, while with some space around it the nebulosity is much more apparent.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-125 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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Scott K
Carpal Tunnel
Reged: 09/13/07
Posts: 1532
Loc: Dallas, TX & Eufaula, OK
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I tried for the Eagle nebula again last night, this time without filters. I used my 20" CDK + 22mm panoptic (157x). SQM ~20.7 I'd guess. (I didn't measure last night. It wasn't bad, but not the best I've had out here either.)
I could see the notch and the pillars without a filter, for what it's worth. With a filter they are pretty obvious. Without a filter, I found it helpful to look for the pillars with averted vision first. They leap out pretty readily for me that way. They were observable with direct vision without a filter, but that was much tougher.
Sorry this is a bigger scope than what the OP is using, and so my report isn't actually that useful.
I will say that this doesn't "feel" as hard as some other dark features in nebula I've looked at. I'd think it should be visible in a 10" scope, although probably not easy. I think the keys are:
1. Having a reasonably dark site. It doesn't have to be pristine, but pretty dark.
2. Having the right magnification / FOV in your eyepiece. You need to be able to see the edges of the nebula, but you also need to have enough magnification to see the pillars, because they aren't large.
3. Get good at seeing dark features in nebula. It turns out I wasn't very good at this for a really long time. (It is arguable that I'm still not very good at it!) Perhaps this is just me, but my brain has been looking for bright stuff for so long that it's happy to overlook the dark stuff in favor of bright stuff. Until I got the hang of how to look for dark features, I really found these types of things to be quite difficult. Even now, now that I have improved quite a bit, and have a much larger scope, I still often find it's helpful to use averted vision first even on relatively obvious dark features. Once I know where to look I often don't have any difficulty seeing them with direct vision. Again, perhaps this is just me.
4. A UHC or OIII filter will help enormously. The boost in contrast in the nebula is quite high.
MM, You mentioned your friend's 20" obsession. If you have a chance, you should take a look through that with an OIII filter. My guess is you'll spot the pillars immediately. I'd also guess that after you know where to look, and what to look for, you'll find it in your scope too.
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zizzapnia
super member
Reged: 05/15/06
Posts: 129
Loc: Virginia
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With my 10" GSO dob from a nice dark sky I can see the nebulosity easily without a filter (also with a 4.5-inch), the dark shape of the eagle/pillars also fairly easily, but not with a well-defined shape. The pillars have never been visible to me with or without a narrowband filter. The dark eagle spot is actually quite small, so try higher powers and then go back to lower power. Having a couple of images helps a lot to know where to look, although stars that are prominent in the scope are all but overwhelmed by nebulosity in images. There's a roughly rectangular asterism with an arc of stars cutting off a corner of the outboard end that helps to locate the the eagle (which is off the other end). I've seen the pillars very nicely in a 30-inch-they're darker than the eagle's "wing," but seeing them at all in a 10 is a real challenge.
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Zizzapnia
http://astronomerica.awardspace.com
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