| A planetary nebula is a remnant of a star of 1-1.5 solar masses that, after its Red Giant phase, ejected its outer layers and contracted to a hot White Dwarf. The ejected gas-layers are expanding with velocities of 20-40 km/sec. The intense radiation of the white dwarf ionizes the gas which lights up in the characteristic colors of a planetary nebula: 656nm (red) for excited hydrogen and 496/501nm (blue/green) for ionized oxygen. Due to the expansion of the gas envelope, the intensity of a planetary nebula drops 'quickly' and after several 10,000 years it becomes too weak for imaging. As a result the number of planetary nebula is limited. |
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DUMBBELL nebula HOO palette August 21/22 and sept. 6/7 2023 25cm Newton f/D=5.7 reduced with simple coma-corrector to f/D=4.6 FTT1010M CCD with Baader 6.5nm H-alpha and OIII filters H-alpha 133*120 sec OIII 128*120 sec FoV: 0.34x0.34 degr |
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PK205 planetary neb. 4, 5 and 7 March 2022 25cm Newton f/D=5.7 FTT1010M CCD with Baader H-alpha filter. 203x2 minute exposures FoV: 0.43x0.43 degr |
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DUMBBELL NEBULA 16 september 2007 25cm Newton f/D=5.7 FTT1010-M CCD RGB-filterweel Exp. RGB 12x90sec FoV: 0.3x0.3 gr |
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ESKIMO NEBULA 27 february 2005 f=4300mm Cassegrain, f/D=16.8 FTT1010-M CCD; MYC-filter wheel Each color: 17x60sec H-alpha component: unsharp masked Image deconvoluted with MEM |
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NGC6781 IN AQUILA 1 September 2003 FTT1010-M (non-binned) Prime focus 25cm Newton MYC-filter wheel Each color 14x100sec. Luminance comp.=M+Y+C images. |
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M57 RING NEBULA and IC1296 23 August 2003 FTT1010-M (non-binned) Prime focus 25cm Newton MYC-filter wheel Each color 18x60s. Unsharp masked IC1296 with other gray-scale pasted into image Luminance comp.=M+Y images. |
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M97 OWL NEBULA 6 April 2003 (excellent seeing) FTT1010-M (binned) Prime focus 25cm Newton MYC-colour filter wheel Exp.: Each colour 15x100sec Unsharp masked; Luminance=sum MYC exposures. |
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DUMB-BELL NEBULA (M27) Date: 23 August 2000 Scope: 25cm Newton at f/D=5.7 CCD: FT1020 colour CCD Exp.: Sum of 29 images of 120sec |
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RING NEBULA (M57), October 1999 25cm Newton f/D=5.7 FT800 with colour filter wheel R 16x1min, G 15x1min, B 17x2min Unsharp masked with HF-structure of R-image. Gamma correction 1.5 |
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ESKIMO NEBULA (NGC2392) 15 mar. 1999 (L), 14 mar. 2001 (R) -"left": FT800, colour wheel, Barlow proj. (f/D=13.4) -Right: FT1020-C, prime focus 25cm Newton (f/D=5.7) Exposure: -FT800: R 21x90s, G 24x90s, B 9x90s -FT1020: 32x90sec Unsharp masked. FOV: 3.8' x 6.0' |