gsETX70
super member
Reged: 12/21/07
Posts: 108
Loc: Fort Worth, TX
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The other night I tried to find the crab nebula from my suburban back yard. I was unable to located it. I live about 10 miles from downtown, so light pollution is high. What will the nebula look like through a 10" Dob? Can it only be seen in dark skies?
Thanks,
Glenn
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Orion XT-10 Classic Dobsonian 254mm
Meade ETX-70 70mm Refractor
Meade 70-AZ-A 70mm Refractor
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stevecoe
Reged: 04/24/04
Posts: 2129
Loc: Arizona, USA
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Glenn;
I can pick it out with my old 8 inch SCT from my backyard in suburban Phoenix. I have no Milky Way and stars to about 5th magnitude in my backyard. At 100X it was a small, pretty faint and elongated 1.5X1 with a somewhat brighter middle.
Hope that helps;
Steve Coe
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150mm 6" f/8 Celestron Refractor on Sirius Mount
80mmED 3" f/7.5 Orion Refractor
Author "Deep Sky Observing" Springer-Verlag
Author "Nebulae and How to Observe Them" Springer
New Canon Xt astrocamera with Hutech modification
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CESDewar
GorillAstronomer
Reged: 01/16/05
Posts: 1811
Loc: Morganton, GA, USA
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Depending on just how bad the LP is, it could be a bit borderline, but should be visible in a 10" DOB. Yes, dark skies make a big difference. I was out 10 minutes ago and had little difficulty catching M1 in my 10x42 binoculars, but I have very good dark skies here (SQM 21.10) and that indeed makes all the difference.
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Edited by CESDewar (02/02/08 01:36 AM)
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gsETX70
super member
Reged: 12/21/07
Posts: 108
Loc: Fort Worth, TX
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Thanks. I'll try again. Could be I was not looking in the right area. I'm still learning to star hop. And, my degree circle is not ready from the printer yet.
Glenn
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Orion XT-10 Classic Dobsonian 254mm
Meade ETX-70 70mm Refractor
Meade 70-AZ-A 70mm Refractor
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Achernar
Post Laureate
Reged: 02/25/06
Posts: 3720
Loc: Alabama, USA
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I can see M-1 from my suburban front yard, in spite of a bright streetlight in front of my house with my 10-inch. However, it's a very faint, irregular patch of light. M-1 is a bright nebula, but unfortunately, it's really best appreciated from a dark site. There, with a 10 or 12-inch telescope, hints of it's chaotic structure come into view. One thing I have notices about this nebula is that nebula filters don't seem to have much effect upon it, except the filaments in it. The nebula overall does not seem to benefit from them, so the only way to get a truly good look at it is a dark night at a place with little or no light pollution.
Taras
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10-inch F/4.5 Discovery Dob
6-inch F/8 Homebuilt Dob
4 1/4-inch F/4 Homebuilt reflector
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Gazer501
super member
Reged: 10/21/07
Posts: 159
Loc: Buckeye, AZ
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Quote:
Glenn;
I can pick it out with my old 8 inch SCT from my backyard in suburban Phoenix. I have no Milky Way and stars to about 5th magnitude in my backyard. At 100X it was a small, pretty faint and elongated 1.5X1 with a somewhat brighter middle.
Hope that helps;
Steve Coe
Hi Steve,
I live in Buckeye and was wondering how far out one most go from the city limits to get good dark skies?
TIA!
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Bushnell 114mm x 900mm
Meade 130MM x 1020MM W/Goto Mount Autostar #494
Zhumell 20 x 80 Binoculars
Binoculars.com Basic Porro 7 x 35 Binoculars
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xfile101
professor emeritus
Reged: 12/08/07
Posts: 739
Loc: Ocean Gate, NJ
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I'm in an LP area where 5th mag stars are about the naked eye limited (depending on the direction I'm looking, South is about 4th mag) and I have see the Crab fairly easily in my 4.5". It's dim for sure but I can see it as a dim irregular smudge. So I would say you should be able to see it without too much problem.
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Orion XT8I
Celestron 114EQ Firstscope
Meade 70mm
Astroscan
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CESDewar
GorillAstronomer
Reged: 01/16/05
Posts: 1811
Loc: Morganton, GA, USA
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I've attached one of my finder charts for M1. To get into the right area, follow a line from the center star in Orion's belt (Alnilam) through the top of Orion (Meissa) and extend that line the exact same amount to run into Zeta Tauri.
With Zeta Tauri in the FOV, look for an arc of three stars closeby which are just a bit under half the way to M1, M1 itself is only 1°8' from Zeta Tauri in the general direction of Elnath in Taurus/Auriga (And, as of the date of this post, Mars). It makes a triangle with HIP26328 and HIP26159, that allows you to accurately pin-point its position.
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Gazer501
super member
Reged: 10/21/07
Posts: 159
Loc: Buckeye, AZ
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Wow!  Thanks again for the concise clear directions to the Crab Nebula! I'll scout it out when it clears up in my area!
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Bushnell 114mm x 900mm
Meade 130MM x 1020MM W/Goto Mount Autostar #494
Zhumell 20 x 80 Binoculars
Binoculars.com Basic Porro 7 x 35 Binoculars
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gsETX70
super member
Reged: 12/21/07
Posts: 108
Loc: Fort Worth, TX
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Thanks for the directions. I'll try again when it clears up. Taras said nebula filters don't seem to do much to enhance the image of M1. Is the same true for the SkyGlow Broadband filter?
Glenn
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Orion XT-10 Classic Dobsonian 254mm
Meade ETX-70 70mm Refractor
Meade 70-AZ-A 70mm Refractor
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6778
Loc: Beatrice, Nebraska
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Quote:
Thanks for the directions. I'll try again when it clears up. Taras said nebula filters don't seem to do much to enhance the image of M1. Is the same true for the SkyGlow Broadband filter?
Glenn
The broadband filters do help somewhat in making the nebula a little easier to see, but they don't provide as much of a boost as a narrow-band "nebula" filter does for emission nebulae. M1 produces a lot of its light over a wide range of wavelengths, so a narrow-band or line filter tends to take away a little of its light. That having been said, I find that of all the filters I have used on M1, the narrowband Lumicon UHC (or its equivalent) provides the greatest contrast of all the filters, with the broadband Lumicon Deep-sky a close second best. Still, the object is faint and diffuse so don't expect too much. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
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WadeVC
Carpal Tunnel
Reged: 12/02/05
Posts: 2799
Loc: Lodi, California,
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Glenn,
I am able to find M1 fairly easily with my 10"...but it took a little time to actually pick it out from the dark background. For me, M1 is quite unspectacular visually.
Anyway, here is a sketch of M1 I made a while back, maybe it will help assist you in knowing what it may look like through the EP of your scope:
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Orion XTi10 f/4.7
Orion XTi8 f/5.9
Meade NGC 70mm f/10
Orion UltraView 10x50 Wide-Angle Binoculars
My Sketch Gallery
My Astronomy Blog
A wise man can see more from the bottom of a well than a fool can from a mountain top.
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gsETX70
super member
Reged: 12/21/07
Posts: 108
Loc: Fort Worth, TX
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Thanks WadeVC. I tried to find it again last night. Using my 32mm EP, I followed the map CESDewar posted and Stellarium. I did not realize most of the stars would show up in my FOV, so I was going too far past it.  Once I got past that, It was easy to follow all the stars. Unfortunately, by the time I found all the guide stars, M1 was over the souther horizion. This is over downtown, so I think the light pollution may have drowned out what little can be seen in M1. I'll try again later this week.
David K., thanks for the filter advice. I'll see if I can buy one of those in the coming months. My car required extensive repairs and I'm now tapped out until I pay off the CC bill.
Glenn
Edited by gsETX70 (02/04/08 10:01 AM)
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Gazer501
super member
Reged: 10/21/07
Posts: 159
Loc: Buckeye, AZ
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Still cloudy here. 
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Bushnell 114mm x 900mm
Meade 130MM x 1020MM W/Goto Mount Autostar #494
Zhumell 20 x 80 Binoculars
Binoculars.com Basic Porro 7 x 35 Binoculars
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proud uncle
Pooh-Bah
Reged: 01/22/07
Posts: 1336
Loc: Central Texas
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Approximately a month ago, I found it fairly easily with my 10" Dob. I have some light pollution, though not bad for southern skies. I knew it was near Zeta Tauri, which I can easily see naked eye. Telrad got me there easily. I was pleased with the view -- I could easily detect the form of a crab's body, though I did not resolve the legs. I expect that's the level of detail a narrow band filter and/or dark skies would give me.
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Kenneth
Zhumell 10" Dobsonian (f/4.9)
2" 32mm WA eyepiece
9mm, 12.5mm, and 20mm Plossls
6mm TMB/BO Planetary
2" 2x ED Barlow
Nikon 10x50 binocular (6.5 deg FOV)
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Regoma
member
Reged: 12/02/07
Posts: 10
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Wade,
Your drawings are almost always STUPENDOUS! I loved your picture mentioned recently of NGC 2169. I wish I could perceive the color you do; maybe my dark adapted eyes are not as sensitive to color as yours. I can see faint stuff -- but it's ALWAYS grey, and the star colors are extremely pale to me: even something like R Leporis!
One thing struck me, however, in the drawings that you and Jeff Young post in these forum discussions, is that the white-on-black views often get too much "competition" from other bright, colorful things on the screen. For instance: though I've set my CRT monitor up with a 16-level greyscale test bar, I still cannot see M1 in your drawing. So I did a negative reversal: and there it was, nicely shown as a faint grey cloud over white. It's not "realistic" but at least the thing is there! I once sent a certain S&T columnist a couple of drawings of mine, and even though I had merely scanned my actual sketch page, in black-on-white, she could not see the faint grey haze that I had sketched in the position of the object: her monitor just had too low a contrast setting. So, she couldn't find the object!
The "normal" night time type view of open clusters works just fine, as the color contrasts and stellar points show up against your black background.
I suspect however that the difficulty of predicting what something will look like on a wide number of monitors is why (for example) the sketches in the Finnish Deep Sky Archive are always black pencil on white background.
At any rate, the reversal of course does not preserve the colors of the stars shown in your M1 field; so that wrecks some of the realism of the stars, though the nebula does show up.
Occasionally also I will just right-click the image itself, and take it away from the forum page, and blow it up full screen: that often helps, too.
Just a thought: both a positive and a negative view of faint fuzzy stuff might be helpful, in case your readers have my particular screen difficulty.
Cheers!
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Olivier Biot
Amused
Reged: 04/25/05
Posts: 14328
Loc: 51°N (Belgium)
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It corresponds to the views of M1 tonight through Koen's C11, although it was a tad brighter. I have to observe more frequently at darker places since before today I never saw M1 
Cheers!
Olivier
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Tal-200K (#199) with JMI NGF-Mini2M focuser on GEM3 • Astro-Tech AT80ED on Orion Sirius EQ-G with EQDIR & home made wireless EQDIRECT • Celestron Regal LX 8x42 & 10x42 • Helios 15x70
ATM 14" f/5 (designing mirror cell and filter wheel/focuser) • ATM 10" f/6 Portable Truss (polishing) • ATM 10" f/25 Dall-Kirkham (primary: polishing, secondary: #120 grit)
AstroForecast
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longfocus
sage
Reged: 02/03/07
Posts: 378
Loc: Sunshine Capital of Canada
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You need a filter. The view is much more detailed then, as David was pointing out. The object is still a faint one though.
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6778
Loc: Beatrice, Nebraska
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Here is a very rough simulation of what M1 seems to look like with averted vision using a 10 inch and a narrowband filter under dark sky conditions. It is only approximate, as the stars are somewhat fainter than shown here, but the detail in the nebula is roughly what you would get as an overall "impression". The main features visible with the filter tend to be the overall elongated shape, the somewhat irregular edges, and the "hook" on the eastern end. You don't see the fine filaments, as they tend to appear more as the tattered edges of the nebula rather than as discreet features. In fact, the only times I have even glimpsed the filaments were with an OIII filter. The OIII made the object smaller, fainter, and more symmetrical in shape, but the filaments just barely began to become visible. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
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Gazer501
super member
Reged: 10/21/07
Posts: 159
Loc: Buckeye, AZ
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I finally got to see it tonight and it appears as a faint fuzzy as posted. Thanks for all the tips and techniques to get to this hard to see DSO. 
(I kinda cheated as I just purchased a Goto Mount) 
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Bushnell 114mm x 900mm
Meade 130MM x 1020MM W/Goto Mount Autostar #494
Zhumell 20 x 80 Binoculars
Binoculars.com Basic Porro 7 x 35 Binoculars
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