Nebula

M42 imaged with SII, H-alpha and OIII narrow-band filters (Baader Planetarium, 6.5-8.5nm bandwidth), shown in three different ways. To the left H-alpha is shown in Red while the OIII image is distributed over Green (100%) and Blue (100%) to obtain the characteristic teal colour. The middle image has the same colour assignment and is unsharp masked, i.e. the luminance of the image was devided by a smoothed version of itself, lowering the intensity of the central part of the nebula and revealing the (nearly overexposed) trapezium star cluster. The image to the right shows M42 with H-alpha again assigned to Red (150%), S-II to Green (400%) and OIII to Green (80%) and Blue (100%). In order to have a clear effect, the Sulfur contribution had to be increased 4-fold.

Images are obtained on february 8, 2023, with the FTT1010-M CCD camera and the f/D=3.5 Newton configuration described below (and in the equipment section, see here). M42 is a relatively bright object and for H-alpha and OIII short, 60-second exposures were needed to avoid overexposure of the central part: H-alpha 19x60 seconds, OIII 30x60seconds. The Sulfur contribution is much weaker and 16 exposures of 120 seconds were acquired.

The images cover a 0.8x0.8 degree field of view, are sharpened and shown with a gamma of 2.2. The luminance is based on the (photopic) eye sensitivity for the H-alpha wavelength (656nm: sensitivity 0.08) and OIII wavelength (501nm: sensitivity 0.34). Thus L=0.08*H-alpha+0.34*OIII.

Horse nebula HOO
14/27/28 february 2023
H-alpha 155x2min
OIII 95x2min
FoV 0.73x0.73 degrees
Gamma 2.0
Intenser red contributions are shown with increasing whiter appearance
The image is sharpened and rotated 90-degrees (CCW)


M42, HOO	M42, HOO, Unsharp masked.	M42, HSO	Horsehead nebula

Images (above and below) obtained with the FTT1010-M CCD camera and my latest Newton telescope. In fact it is a modified Cassegrain telescope with a 25cm, f=1091mm primary. By adding a plane-convex lens close to the CCD the effective focal length is reduced to f=880mm and the f/D is improved from 4.3 to 3.5. Without this lens, coma of the parabolic primary over the 12mmx12mm focal plane of the CCD is substantial. The plano-convex lens reduces coma and increases sensitivity by some 50% (which compensates for the relatively low quantum efficiency of the CCD's I'm (still) using). For more details click here.
The images are cropped to 0.5x0.5 degrees of the 0.8x0.8 degrees field of view. The bandwidth of the H-alpha and OIII filters are 6.5nm and 8.5nm (Baader-Planetarium).

Bubble nebula
NGC7635
19 nov, 12/14 dec 2022
25cm Newton f/D=3.5
Exposure:
H-alpha 76x120sec
OIII 93x120sec
Cropped FoV: 0.50 x 0.50 degr

Crescent nevel
NGC6888
20/23 aug, 1/21 sep 2022
25cm Newton f/D=3.5
Exposure:
H-alpha 94x120sec
OIII 149x120sec
Cropped FoV: 0.52 x 0.52 degr


M1, revisited: H-a: Febr. 25..27, 2022 SII,OIII: Jan 28, 2011 25cm Newton f/D=5.7 FTT1010M CCD with SHO-filter wheel H-alpha: 151x120sec SII,OIII: 26x120sec FoV: 0.37x0.28 degr	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	M1 Crab nebula January 28, 2011 25cm Newton f/D=5.7 FTT1010-M CCD with SHO-filter wheel Lum.: H-alfa and OIII image stacks Exp. SHO: 25x120 sec. FoV: 0.26x0.26 degr.

Images made with the FTF2020-M CCD camera equipped with a Baader H-alpha filter (7nm bandwidth) and with either the 25cm Newton using a coma-corrector resulting in f/D=4.7 or a Leica f=300mm teleobjective at F#4

IC1848 Eastern part
2 jan 2009
25cm Newton f/D=4.7
Exposure: 84x150 sec
Field of View: 1.1 x 1.0 degr.

IC1805 and 1848
27/28 dec 2008
f=300mm Leica teleobj.
Exposure: 66x3 min
Field of View: 4.6 x 3.5 degr.

IC410
30 dec 2008
25cm Newton f/D=4.7
Exposure: 55x150sec
FoV: 0.9 x 0.9 degr.

IC405
29 dec 2008
25cm Newton f/D=4.7
Exposure: 59x150sec
FoV: 1.1 x 0.8 degr.

Auriga nevels
IC405, IC410 en IC417
27/28 dec 2008
f=300mm Leica teleobj.
Exposure: 112x3 min
FoV: 4.6 x 4.4 degr.


IC59&IC63, 7 december 2008 25cm Newton f/D=5.7 with coma-corrector f/D=4.7 FTF2020-M CCD Baader H-alpha filter 31 exposures of 3 min. FoV: 1.1x0.9 degr	IC443, 10 february 2008 25cm Newton f/D=5.7 FTF2020-M CCD with Baader H-alpha filter 54 images of 150 sec FoV: 0.90x0.85 degr	Detail Pelican nebula 22 october 2007 25cm Newton f/D=5.7 FTF2020-M CCD, binned Baader H-alfa filter Exposure: 50x180sec waxing gibbous moon nearby! FoV: 0.79x0.95 degr	NGC7635 and M52 13 october 2007 25cm Newton f/D=5.7 FTF2020-M CCD Baader H-alfa filter Exposure: 29x180sec FoV: 0.93x0.93 degr

Veil nebula west 13 and 14 october 2007 25cm Newton f/D=5.7 FTF2020-M CCD Baader H-alfa filter Exposure: 59x180sec FoV: 0.67x0.93 degr	vdB142 in IC1396 15 september 2007 25cm Newton f/D=5.7 FTF2020-M CCD, binned Baader H-alpha filter Exp.: 41x150sec FoV: 0.95x0.82 gr	Planetary nebula PK205 22 january 2007 25cm Newton,f/D=5.7 FTT1010-M CCD H-alpha filter (10nm) Exposure: 48x100sec. FoV: 0.36x0.36 gr.	NGC1491 22 january 2007 25cm Newton,f/D=5.7 FTT1010-M CCD H-alpha filter (10nm) Exposure: 55x90sec. FoV: 0.28x0.28 gr.

North America and Pelican nebula, 15 october 2006 300mm f#4 teleobjective FTF2020-M CCD H-alpha filter (10nm) Exposure: 24x3min. FoV: 4.5x4.5gr.	NGC6888 Crescent nebula 20 september 2006 300mm f#4 teleobj. FTT1010-M CCD H-alpha filter (10nm) Exposure: 83x90 sec FoV: 0.44x0.44gr.	M17, Swan or Omega nebula 4 july 2006 25cm Newton,f/D=5.7 FTF2020-M CCD H-alfa filter (10nm) Exposure: 30x80sec FoV: 0.96x0.96gr.	M16, Eagle nebula 3 july 2006 25cm Newton,f/D=5.7 FTF2020-M CCD H-alfa filter (10nm) Exposure: 58x60sec FoV: 0.96x0.96gr.


IC1801 and Melotte 15 19 december 2004 prime focus 25cm Newton FTF2020-M with H-alpha filter and coma-corrector at f/D=4.7 Exposure: 44x3 minutes Field of View: 1.1x1.1 degrees Lower detail: 0.66x0.44 deg.	NGC281 and IC1590 23 november 2004 prime focus 25cm Newton FTF2020-M with H-alpha filter and coma-corrector at f/D=4.7 Exposure: 59x2.5 minutes Field of View: 0.7x0.7 degrees Lower detail: 0.3x0.2 deg.	Veil Nebula 11 october 2004 f=300mm teleobjective at F#5.5 FTF2020-M with H-alpha filter(Bandwidth 10nm) Exposure: 56x3 minutes Field of View: 4.0x4.0 degrees	Veil Nebula East (NGC6992) 30 september 2002 Prime focus f=1455cm Newton scope at F/D=5.7 FTF2020-M with RG630 and IR cutt-off filter Transmission 630-720nm Exposure: 35x2 minutes Field of View: 1x1 degree.

On the "left", a recently taken image of nebulae in the vicinity of Gamma-Cygni is given. A f=300mm tele-objective, fitted with an H-alpha filter (Edmund optics) was used to create this nearly 5x5 degrees field of view. Some distinctly bright and dark nebula are visible of which three were photographed previously in more detail using the 10" Newton (f=1455mm).


H-alpha nebulae around Gamma-Cygni 9 and 15 september 2004 FTF-2020M CCD (no binning) f=300mm tele-obj. and H-alpha filter Stack of 118 images of 3 min. Field of view: 4.7x4.7 degrees	IC1318 North 2 September 2004 FTF2020-M (binned) Prime focus 10" Newton Band filter RG630+IR-filter (transmission 630-720nm) Exposure: 57x2 minutes FOV: 1x1 degrees	NGC6888 Crescent nebula 5 October 2003 FTT1010-M (binned) Prime focus 25cm Newton, f/D=5.7 H-alpha filter Exposure: 29x150sec FOV: 0.45x0.45 degr. Imaged with Gamma=2	IC1318 East and LDN889 6 October 2002 FTF2020-M (binned) Prime focus 10" Newton Band filter RG630+IR-filter (transmission 630-720nm) Exposure: 42x2 minutes FOV: 1x1 degrees

	Emission nebula IC1805 (Running Dog nebula) and IC1848. 18 DECEMBER 2003 FTF2020-M in binning mode with f=300mm Telelens F#5.5 H-alpha IF-filter 10nm bandwidth Exposure: 54x3min FOV: 4.7x3.5 degr.		Emission nebula IC1396 15+18 October 2003 FTF2020-M with f=300mm Telelens F#5.5 H-alpha IF-filter 10nm bandwidth Exposure: 15 oct 32x3min binned 18 oct 36x4min non-binned FOV: 3.4x3.4 degr.
	IC5146 Cocoon nebula 24 September 2003 FTF2020-M (binned) Prime focus 25cm Newton With simple coma-corrector (description follows soon) H-alpha IF-filter 10nm bandwidth Exposure: 35x150sec		NGC6820/6823 14/24 September 2003 FTF2020-M (binned) Prime focus 25cm Newton With simple coma-corrector H-alpha IF-filter 10nm bandwidth Exposure: 69x150sec

These images are captured with my latest CCD-camera with FTF2020-M CCD chip (2048x2048 monochrome chip)
in binning mode (1024x1024 pixels of 24x24 um)

The here presented four images are made using an H-alpha IF-filter (10nm bandwidth, Edmund Optics)


Cone Nebula 13/14 March 2003 f=145cm Newton 0.7x0.9 degr. 99x2.5 minutes at 70% illum. Moon!	Rosette Nebula 21 February 2003 f=145cm Newton 0.9x0.9 degr. 67x2 minutes Limit magn. 4 !	Horsehead Nebula 20 February 2003 f=145cm Newton 0.9x0.9 degr. 50x2 minutes Limit magn. 4 !	California Nebula 8 December 2002 f=300mm tele-objective, f/D=5.5 4.3x3.0 degr. 46x3 minutes

Images below:
Prime focus f=1455cm Newton scope at F/D=5.7, D=255mm. Field of View: 1x1 degree.
RG630 and IR cutt-off filter. Effective transmission 630-720nm and thus mainly H-alpha.
Image grey scale with Gamma=2 to reveal the weaker parts of the nebula.


IC1795 Cassiopeia 9 november 2002 46x2 minutes		IC1318 en LDN889 East of gamma-cyg. 6 october 2002 42x2 minutes		Veil nebula East part (NGC6992) 30 september 2002 35x2 minutes		North America Nebula Southern ridge 13 september 2002 53x2 minutes

	North America en Pelican nebula 2 september 2002 FTF2020-M CCD, binned 300mm Telelens F/D=5.5 RG630 and IR filter (630-720nm) Sum of 28 exposures of 3 minutes		M16, 2 june 2002 25cm Newton, f/D=5.7 with FTF2020-M Shortly visible between trees: 19x15sec Image grey scale with Gamma of 2
	Rosette nebula (NGC 2237-39), 7 March 2002 FTT1010-M with f=300mm telelens (f/D=5.5) and H-alfa filter Sum of 25 exposures of 3 minutes The image is slightly sharpened		Horsehead nebula (2 february 2002) CCD: FTT1010-M equipped with f=300mm telelens and H-alfa filter Sum of 21 exposures of 3 minutes The image is shown with a gamma of 1.3
	M78 (NGC2068, 2067, 2064), 14 December 2001 Scope: 25cm Newton, f/D=5.7 CCD: FTT1010-M Exposure: 41x60sec Gamma=3 to show bright and weak features		CRAB NEBULA (M1), 30 January 1999 25cm Newton f/D=5.7 FT800 with RG610 and IR-blocking (610-720nm and thus H-alpha) sum of 20 images of 120 sec Slightly unsharp masked
	ORION NEBULA (M42) 25 february 2001 25cm Newton at f/D=5.7 CCD: FT1020-C Sum of 26 images of 120sec		ORION NEBULA (M42), 25 february 2001 Same image as "left", now unsharp masked
	ORION NEBULA (M42), 29 Januari 1999 Scope: 11cm Newton f/D=4.7 CCD: FT800 with colour filter wheel Exposure: R 8x2min, G 9x2min, B 16x2min Remarks: Gamma correction 1.5		CENTRAL PART of Orion nebula 30 Januari 1999 Scope: 25cm Newton f/D=5.7 CCD: FT800 with colour filter wheel Exp.: R 6x1min, G 6x30sec, B 8x1min Slightly unsharp masked, gamma correction 1.5