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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4114
Loc: Ireland
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We've seen quite a bit of cloudcover this month (and July was the wettest in 50 years), but at least the first clear night in recent memory happened to coincide with a new moon.
I had some NGC PNs and Arp Peculiars on my list, and a few challenge objects (Minkowski's Footprint and a couple of Abell PNs), but in the end I spent so much time sketching the Fetus and hunting down Minkowski's that I never got to the Arps or Abells.
Quote:
NGC7023 Iris Nebula 8/21/2009 22:11 UT; Pickering 7, NELM 6, SQM 20.6
16" Mak-Cass @ 235X
First impression at 150X is a bit of glare around a bright field star but further study reveals a much larger extent and a non-uniformity to the haze. 235X a bit better with more contrast and a more accentuated "bite" out of the nebulosity to the WSW. 335X washes out too much nebulosity. Further study reveals brighter crescent to N and brighter angular section fanning out to SSW.
UHC decreases extent and variances in brightness; OIII reduces extent even further (but seems to have less effect on variegation).
Quote:
NGC7008 8/21/2009 22:41 UT; Pickering 7, NELM 6, SQM 20.6
16" Mak-Cass @ 235X, UHC
150X + OIII brings out clumping most; 335X unfiltered shows involved stars best; 235X + UHC most balanced. I didn't see the detached lump on the spine this time, but I got a few brief moments that showed the double arc to the head. Field littered with double stars.
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NGC7048 8/21/2009 23:11 UT; Pickering 7, NELM 6, SQM 20.6
16" Mak-Cass @ 153X, OIII
Mottled gray ball at 335X. Two averted-vision stars involved, neither holdable but the brighter of the two (to NW of center) perhaps 30% at 450X and 40% at 600X. Dimmer one (near N edge) no better than fleeting at any magnification.
Possible minima to center at 75X with OIII; 150X and OIII reveals hints of same and some fringing to NE.
Quote:
M1-92 Minkowski's Footprint 8/21/2009 23:30 UT; Pickering 7, NELM 6, SQM 20.6
16" Mak-Cass @ 597X
Wow, is this one tiny! Completely stellar in appearance up to 335X; hints of elongation at 450X; with bipolar nature only apparent at 600X. Looks like a fairly fuzzy notched double with the ESE component about 1/3 to 1/2 the size of the WNW component.
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-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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skyward_eyes
Carpal Tunnel
Reged: 12/12/06
Posts: 2101
Loc: Arizona
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Nice job. I need to try the Fetus in my 16". I also need to try the Iris, I have yet to try Minkowski's objects.
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www.skywardeyes.webs.com
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8273
Loc: Beatrice, Nebraska
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Since NGC 7023 is mainly a reflection nebula, the UHC and OIII filters do not help it very much. In fact, as you indicated, filters actually hurt it somewhat. About the only filter that seems to help at all is a broad-band filter like the Lumicon Deep-sky or Orion Skyglow. I have seen Minkowski's Footprint in my 9.25 inch f/10 SCT, although it was considerably easier to see in a 20 inch Obsession at the Nebraska Star Party last year. There is a nice large but faint supernova remnant (Sh2-91) only about 45 arc minutes to the northeast of Minkowski's Footprint. It appears similar to the "Witch's Broom" portion of the Veil, only considerably fainter and somewhat smaller (26' x 3' arc). We got a pretty good look at it in a 25 inch Obsession with the OIII filter, but I haven't been able to see it in my own scope. 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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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4114
Loc: Ireland
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Thanks, guys.
David, funny enough I thought about trying my DeepSky filter, but since I had such poor luck with the other two on 7023 I skipped it. (Generally speaking I only use it for targets below 20° of altitude where my background sky washes out.)
I'll have to put Sh2-91 on my list, although it sounds like it may be out of my reach.
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-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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