proud uncle
Carpal Tunnel
Reged: 01/22/07
Posts: 1688
Loc: Central Texas
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Quote:
Kenneth --
One other thing I didn't mention: even without a rising heat source, the seeing can vary markedly from minute to minute. When observing planets, I usually spend a good 15 to 30 minutes at the eyepeice -- during which I'll likely get 4 to 10 moments, each maybe 1/2 a second to several seconds long, which are of considerably better seeing than the rest of the time.
-- Jeff.
I do the same thing, and know what you are saying. Even observing the Trapezium, I spent probably 10-15 minutes at the eyepiece, and only caught one glimpse -- maybe 1-2 seconds duration of component E.
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Kenneth
Nikon 10x50 binocular
Zhumell 10" Dobsonian (f/5)
eyepieces: 32mm (2" WA), 20mm, 12.5mm, 9mm (EWA), 6mm (TMB/BO Planetary), and 2X Barlow
Wratten filters: #21, 25A, 47, 56, 80A, and ND13
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rtroxel
super member
Reged: 08/14/06
Posts: 373
Loc: Maryland, USA
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Quote:
Mt Pinos is usually very good, it's about an hour and a half from me (eastern L.A. County). I usually go to the northern Mojave near Death Valley to get really dark mag 7 skies. The LP is bad here but the seeing is usually pretty good, just wasn't Monday.
Where do you go in the Mojave? Is there a state park (for observing) there? I'm visiting my relatives in San Diego in a few months, and I'm looking for dark sky sites in the Southwest.
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12.5" Obsession #1541
w/ArgoNavis
EPs: 35mm Panoptic, 12mm and 9mm Naglers
2X 2" Powermate
Harford County Astronomical Society
Maryland
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F.Meiresonne
Post Laureate
Reged: 12/22/03
Posts: 4136
Loc: Eeklo,Belgium
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Quote:
Quote:
.... Could rising heat currents from neighbors homes be limiting my ability to resolve components E and F?
Absolutely. Even rising heat off of asphalt or concrete could. (And rising heat off of fellow observers can effect planetary detail, althogh perhaps not the visibility of E and F.)
-- Jeff.
There a lots of things that can spoil the view.Don't know why but few weeks ago i tried (quickly) the E en F component. No trace whatsover.
Yesterday i tried it again when Orion was straight south. I guess everything was right because it was absolutely no problem to see botch components this time. Actually i was quite easy. Allthough too much magnification and the F component tend to dissapear again.
I guess the other time seeing was not good, collimation perhaps could have been better and my mirror was probably not cooled down yet. It was quite a huge difference....
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Freddy
Obsession 18 inch #1638
Orion Optics 8 inch F/4.5 -1/8 wave optics -Vixen GP-E
22x85 Helios Apollo (=GO SS)
15x70 TS Marine (=Obie Ultra)
10x60 Helios Quantum 4(= Obie Mariner)
10x50 Fujinon FMT-SX
10x50,8x40 Helios Nature sport plus
Eyepieces in use :Pan 35,24,19, N13T6, Pentax 10, 7 XW, N9T6, TV2, BGO 12.5, 9 mm
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Scanning4Comets
Markus
Reged: 12/26/04
Posts: 10114
Loc: Deep Space!
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That drawing with the 16" is very very accurate and mind blowing!!! 
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Markus
10" F/4.7 Modified Skywatcher Reflector, 38mm Orion Q70, 22mm Vixen LVW, 14mm Denkmeier, 10mm Pentax XW, 7mm Pentax XW, 5mm Vixen LVW, 2" GSO 2x ED Barlow, 2" DGM O-III, Custom Laminated Star Charts, Uranometria 2000 Custom made maps with custom made rotating map holder, Astro Cards, Seen All Messier, Hundreds of NGC, Working on Herschel 400, Star hopper for over 30 yrs.
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4491
Loc: Ireland
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Thanks, Mark!
Hey, is that a telescope I see in your sig line? Are you back from your binocular hiatus?
-- Jeff.
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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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Starman1
Vendor (EyepiecesEtc.com)
Reged: 06/24/03
Posts: 17639
Loc: Los Angeles
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Gadzooks!
Most people must observe in heavy light pollution!
In a dark sky, as I mentioned, the Orion nebula appears more than a degree wide and is connected to NGC1977 with a bridge of nebulosity. It overlaps the Sword stars on both sides. The overall shape is a ring with the Trapezium area merely the bright diamond on the ring.
The view drawn in the 16" post resembles the view through a 6" at about 100X under dark skies with the exception that the tiny details drawn do exceed what's visible in 6". That drawing tells me more about how hard it is to draw than what's visible in a 16".
I've seen the Huyghenian area appear like flocculent clouds in a 16", with individual stars in a Swiss-cheese-like structure in each "hole".
At over 200X, the Trapezium resolves into 7 and occasionally 8 stars in my 12.5", but this is seeing-limited, not aperture-limited.
Try high powers on the central area to see more detail--at 250-300X, the central area displays more detail than can be drawn, with a host of superimposed stars.
Last, the nebula appears dramatically different with different nebula filters. A UHC filter will show the entire ring shape to a 6-8" scope and there will be a lot of detail seen. An O-III filter shows the tiny details in the central region and shows the "Wings" to be a series of "ropes" all mixed together with 12".
I give kudos  to anyone trying to draw the nebula. One could easily spend all night and never successfully represent what's visible.
This nebula has it all:
--great in binoculars of 20X and more
--great in modest apertures
--stupendous in larger apertures, with lots of color in 20" and more.
--not so good in the very largest apertures (60") because the field of view is too limited. However, one can see 10 stars or more in the Trapezium.
And great in both hemispheres to boot!
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Don Pensack
www.EyepiecesEtc.com
12.5" Teeter/Zambuto, 5" Maksutov
Sustaining Lifetime IDA member
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F.Meiresonne
Post Laureate
Reged: 12/22/03
Posts: 4136
Loc: Eeklo,Belgium
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Quote:
Most people must observe in heavy light pollution!
True in my case. I am sure from my backyard i see less in my 18 inch then you at your dark place with a 12.5.
There is no substitue for a dark clear sky.
But i just have to live with it. Still i am always curious to deep i can go from a lightpoluted Belgian backyard.
Well, so far a 14 m galaxie showed up, not so bad afterall...
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Freddy
Obsession 18 inch #1638
Orion Optics 8 inch F/4.5 -1/8 wave optics -Vixen GP-E
22x85 Helios Apollo (=GO SS)
15x70 TS Marine (=Obie Ultra)
10x60 Helios Quantum 4(= Obie Mariner)
10x50 Fujinon FMT-SX
10x50,8x40 Helios Nature sport plus
Eyepieces in use :Pan 35,24,19, N13T6, Pentax 10, 7 XW, N9T6, TV2, BGO 12.5, 9 mm
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4491
Loc: Ireland
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Quote:
.... Most people must observe in heavy light pollution! ....
To be fair, the thought behind the sketch pair was to compare the difference between 18x70 and 175x400. The binos don't have multiple powers (or filters), so I didn't use multiple powers (or filters) with the SCT either.
I *did* sketch pretty much everything I saw. My worst light pollution is to the south, and M42 never rises above 30° altitude for me -- I'd guess my NELM in that area of the sky is about 4.5.
Cheers,
-- Jeff.
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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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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4491
Loc: Ireland
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So, to round things out, I went ahead and did one at higher power (510x) with a UHC filter. There's enough going on at this magnification that it's getting much more difficult to sketch -- so I make no claims that this one contains most of what I saw.
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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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