Click here if you are having trouble logging into the forums
Privacy Policy |
Please read our Terms
of Service | Signup and
Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User
stevek
Pooh-Bah
Reged: 04/16/06
Posts: 1207
Loc: west michigan
|
|
I spent the wkend camping in a dark site, nelm est 5.5-6, and had scope along. While I was exhausted after a very active day, I was at least 1.5 hrs fully dark adapted. N Amer and Veil were distinct in scope and binocs without filters. PNs 6781 & 6852 were nice and fairly easy too. I'd never looked but saw it in PSA and tried for it. It was a VERY rich star field and I never did find it. I vaguely remembered it was larger and was using the 13mm (92X- .7 deg fov) with and without the NPB filter. I'm looking for some hints I guess. Did I just overlook it or is it very faint and requiring more time/effort?
Steve
--------------------
DSO 8" f6 DOB w/ 8x50 RACI & 2"Crayford
1958 Sears Discoverer 76mm Refractor
GSO SV 30mm 2",21mm Hyp,13mm Strat,BO/TMB ver2-6mm & 4mm
1.25"Filters: DGM-NPB, 25%ND
1.25" plossls: 25mm,20mm,15mm,9mm
Orion 2X Shorty Barlow
Garrett Gemini LW 11x56mm binocs
BTG-10 4.0mW green laser pointer
"What is that burning in the sky? Tell me y'all..." Jeff Beck/Jan Hammer
|
cildarith
Carpal Tunnel
Reged: 08/26/04
Posts: 2084
Loc: San Diego, CA
|
|
Hi Steve, NGC 6888 is very faint; on all but the very best nights (at my ~6.5 NELM site) it is just about invisible in my 6-inch scope. Add an OIII filter, however, and it is quite easy.
--------------------
Eric
6" f/6 Parks Newtonian
10x50 Bushnell Binocs
CN Sketch Gallery
|
DeepSpaceTour
Carpal Tunnel
Reged: 10/25/05
Posts: 2942
Loc: In the dark and"WAY"out there!
|
|
Funny you post this,I was out last night at a fairly dark site nelm 5.8 approx. with my 6" refractor, and I was observing all the bright nebula I could, up through Cygnus and Cepheus,where there are a lot of them up through this region, 6888 being one of them,it was easily visible through my 31MM wide field and an Ultra Block filter,sometimes the 0III can be a bit to aggressive in a 6" scope but other times the 0III is just the ticket,you have to experiment,last night I found the Ultra Block to be working great in the 6" refractor.The Crescent nebula is quite an interesting object,choosing a filter that works best through a 6" scope, is a key element to teasing out any detail NGC-6888 has to offer.
Clear skies.
--------------------
-------------------------
Bill
-17.5"F/5 Discovery"Truss" Dob/Dob driver/ArgoNavis
Kendrick dew control/Obsession Alt bearings
-Orion 4.5" StarBlast "SOLD" waiting for the 6"
-Antares 152-F/6.5 refractor on HEQ-5 Pro
-15x70 Binocs
-Collimating tools "LOTS"
- TV ep's *8-Ethos*13-Ethos*26T-5*31T-5*
- 2" Barlows
- Pelican1600
|
Dave Mitsky
Postmaster
Reged: 04/08/02
Posts: 5707
Loc: Pennsylvania, USA
|
|
I've never observed NGC 6888 through a 6" telescope but it was a fairly easy target through a friend's filtered 180mm TMB achromat from a mid-sixth magnitude site two Sunday nights ago.
Dave Mitsky
--------------------
Chance favors the prepared mind.
De gustibus non est disputandum.
|
sgottlieb
sage
Reged: 07/22/07
Posts: 232
Loc: SF Bay area
|
|
With a little bit of care, NGC 6888 is even visible in my 80mm finder using an OIII filter --
80mm finder: using 25x and an OIII filter, the brighter eastern side of the shell was clearly visible and appeared locally brightest in an elongated arc on the north side passing through mag 7.2 HD 192182. A very faint hazy glow with no structure completed most of a large oval.
Lots of structure in larger scopes --
17.5": Stunning view at 100x (20mm Nagler) using an OIII filter. The outline appears as a huge, irregular cosmic egg, ~18'x11', floating in a very rich Cygnus star field. The complete annulus is easily visible. The brightest section is along the north side and passes through a mag 7.2 star at the north edge. This piece displays much structure with several knots and wispy tendrils. An isolated bright knot is within the weakly glowing interior and is collinear with the mag 7.2 star and the mag 7.4 central star. The interior has an irregular surface brightness with wispy striations that appear to radiate from the central star towards the NW rim at the end of the bright arc. The rim is widest on the SW end with more nebulosity filling in towards the center. The fine texture and structure of the nebulosity creates a 3-dimensional feel and an "electric" effect.
--------------------
Steve Gottlieb
18" f/4.3 Starmaster
Adventures In Deep Space - New article on MASH planetaries
7500+ NGC/IC Visual Descriptions
NGC/IC Project
|
Bill Weir
scholastic sledgehammer
Reged: 06/01/04
Posts: 780
Loc: Metchosin (Victoria), Canada
|
|
The brightest section is wrapped around an asterism of stars that reminds me of the "Keystone" of Hercules. When locating it I don't even look for the nebulosity I just focus on the spotting the asterism.
From my backyard with a SQM of around 21+, it's faint but rather easy with my 6" dob. This is even without a filter. Add an OIII or Ultrablock and even a rookie can see it if it's on the object already. Then again if I didn't know what I was looking for I could easily pass it by.
Bill
--------------------
6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar II ED Doublet
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2007, 171.
So far in 2008, 100
|
LumpyDarkness
sage
Reged: 08/06/07
Posts: 292
Loc: San Francisco bay area
|
|
Quote:
I spent the wkend camping in a dark site, nelm est 5.5-6, and had scope along. While I was exhausted after a very active day, I was at least 1.5 hrs fully dark adapted. N Amer and Veil were distinct in scope and binocs without filters. PNs 6781 & 6852 were nice and fairly easy too. I'd never looked but saw it in PSA and tried for it. It was a VERY rich star field and I never did find it. I vaguely remembered it was larger and was using the 13mm (92X- .7 deg fov) with and without the NPB filter. I'm looking for some hints I guess. Did I just overlook it or is it very faint and requiring more time/effort?
Steve
Based on your seeing the Veil and NAN without filters, I suspect you should be able to observe the Crescent without much difficulty when using an NPB or similar filter. Perhaps it was just your being tired. What is a PSA?
Here is my observation of the Crescent from last week, bigger scope, darker site:
N6888 Cyg BN 18.0'x8.0' 20 12 01 38 23 00
8/1/08 174X NPB, Sh2-105, Crescent Nebula. Located almost a third the distance along a line from Gamma to Eta
Cygni. The views of this object each year at Lassen replace the past ones as "the best" and this
year was no exception. The fine wisps of nebulousity interior to the egg shaped shell, especially
inside the thick bottom band, was amazing. Detail could be picked out all the way across from one
side, through the Wolf-Rayet progenitor star, to the other side of the shell. This is a great
object at Lassen, where it is in the same class as the Veil Nebula for visual beauty.
Clear skies,
--------------------
Mark Wagner
18" f/4.5 Dob
The Astronomy Connection: Observing Reports - updated 9/29/08
Adventures In Deep Space: updated 9/29/08
|
scopethis
sage
Reged: 05/30/08
Posts: 239
Loc: Kingman, Ks
|
|
My notes show that I saw the Cresent's ghostly "C" shape with a 10" @ 64x. Some portions were brighter than others. No filter was used. The object should be easily visible in an 8" scope. Just one note though, it was at a very dark site.
|
Spaced
Carpal Tunnel
Reged: 03/01/05
Posts: 1655
Loc: Tacoma, Washington, USA
|
|
Quote:
The brightest section is wrapped around an asterism of stars that reminds me of the "Keystone" of Hercules. When locating it I don't even look for the nebulosity I just focus on the spotting the asterism.
Thanks for the tip! I'll check it out again in a couple of days with that in mind.
FWIW, I had no trouble locating the Crescent in my 10", w/o filter, at my dark sky site a couple of days ago. It was faint but readily visible. I didn't add a filter, but should have. I will next time.
--------------------
Mike
Look! Up in the sky!
_____________________________
XT 10i - the i stands for Telrad
Megrez II 80 ED Triplet APO "Punk"
Siebert Black Night BVs
8 X 42 Celestron Regals
|
stevek
Pooh-Bah
Reged: 04/16/06
Posts: 1207
Loc: west michigan
|
|
Thanks folks - I just think I was a doofuss and couldnt orient to the right stars. It was a LONG day at the beach with many fermented beverages  and I added a hard 6 mile hike during the hottest part of the day with a 30 lb. pack as part of a warmup for a trip next week, followed by a campfire evening... all before I set up at midnight... I'll chalk up this miss as a "duh" and go for it my next dark night out. BTW - PSA referred to my Sky & Telescope Pocket Sky Atlas.
Steve
--------------------
DSO 8" f6 DOB w/ 8x50 RACI & 2"Crayford
1958 Sears Discoverer 76mm Refractor
GSO SV 30mm 2",21mm Hyp,13mm Strat,BO/TMB ver2-6mm & 4mm
1.25"Filters: DGM-NPB, 25%ND
1.25" plossls: 25mm,20mm,15mm,9mm
Orion 2X Shorty Barlow
Garrett Gemini LW 11x56mm binocs
BTG-10 4.0mW green laser pointer
"What is that burning in the sky? Tell me y'all..." Jeff Beck/Jan Hammer
|
|
8 registered and 3 anonymous users are browsing this forum.
Moderator: matt, Olivier Biot
Print Thread
|
Forum Permissions
You cannot start new topics
You cannot reply to topics
HTML is disabled
UBBCode is enabled
|
Thread views: 226
|
|
|
|
|
|
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
