Clic here for 60% size 1919x1498 (885 kB)
This is a cooperative project together with my colleage Bernd Wallner from southern Germany.
During the past weeks we both aimed our telescopes for a total 19h exposure to detect a very faint unknown nebula (center of the image) and surroundings.
Myself: 410mm cassegrain in corrected prime focus at f/3
About this Image
The image is centered on RA 22 41 47, DEC +37 42.9, north is to the left.
This nebula is catalogued as LBN 438 (Lynd's catalogue). However we could not find any image from this object, so we think, it is a premiere.
This is a beautiful example of galactic dark nebulae at high latitudes that become visible through illumination by the interstellar radiation field this is known as Extended Red Emission (ERE).
ERE is a dust-luminescence process, which appears in a broad band extending in wavelength across the R-band.
ERE also often appears in narrow filaments on the edges of clouds and may therefore be mistaken for H-alpha emission.
This nebula emits no significant H-alpha signal. It's shape reminds of a cometary globule in its very last phase before being dispersed.
Below you find a 30/60 % crop on the center of the above image (field of the Bernd's ST-10 with his 24" f/3).
Technical Details
Optics
Bernd: 600mm cassegrain in corrected prime focus at f/3
Mount
Myself: MK-100 GEM
Bernd: homemade GEM
Camera
myself: SBIG STL-11000M at -15C, internal filter wheel
Bernd: SBIG ST-10XME
Filters
Astronomik LRGB
Date
Sep 07 - Oct 16, 2005.
Location
Wildon/Austria and Burghausen/Germany
Sky Conditions
mag 5 sky, raw FWHM 2.5-3"
Exposure
Myself: L:R:G:B = 150:90:60:120 minutes (10-minute sub-exposures)
Bernd: L:R:G:B = 120:180:180:240 minutes (10-minute sub-exposures)
Processing
Image aquisition, calibration and color combine in Maxim DL 4.10;
image blending, levels, curves, color balancing, light unsharp mask in Photoshop;
Noise reduction by Neatimage