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Thursday, September 8, 2011

Info Post











Since my processing technique gets better and weather doesn't give any support, I have reprocessed some older images. There is now star colors added and other processing is tweaked too.







Messier 27, the "Dumbbell Nebula"




Ra 19h 59m 36.340s Dec +22° 43′ 16.09″








Image is in HST-palette, (HST=Hubble Space Telescope) from the emission of ionized elements, R=Sulfur, G=Hydrogen & B=Oxygen.Star colors are mixed from the NB channels, Red=H-a, G=O-III & B= 85%O-III + 15%H-a.








I redid the composition too, the old one was little too static to my taste, image is cropped.



The Dumbbell Nebula (also known as a Messier 27, M 27, or NGC 6853) is a planetary nebula in the constellation Vulpecula, at a distance of about 1360 light years. It has a large angular diameter as a planetary nebula, about 8 x 5,6 arc minutes. (Rarely imaged outer halo is not included, it can be seen in my image. With an outer shell, the diameter is over 15'' (more than a size of the half a Moon))

Planetary nebulae are shells of gas shed by stars late in their life cycles after using up all of their nuclear fuel. The star then ejects a gaseous shell, which is illuminated by its extremely hot central star, a core left from the original star. n this image, the central star is clearly visible at very center of the nebula. M27's central star has a magnitude of 13.5 and is an extremely hot blueish dwarf with a temperature of about 85,000 K.

Our own star, the Sun, is expected to undergo the same process in a couple of billion years.











Natural color composition from the emission of ionized elements, R=80%Hydrogen+20%Sulfur, G=100%Oxygen and B=85%Oxygen+15%Hydrogen to compensate otherwise missing H-beta emission. Star colors are mixed from the NB channels too.This composition is very close to a visual spectrum.








This is the whole field image with the old composition.







Previous version of the M27 can be found here:














Details:


Camera, QHY9


Optics, Meade LX200 GPS 12" @ f4.65


Guiding, Lodestar and SXV-AO @ 13Hz


image scale is 0.8 arcsecond/pixel





Exposures: 


9x1200s  Binned 1x1+ 7x600 Binned 2x2 with 7nm H-alpha filter 


6x600s, binned 2x2, for O-III 


2x600s, binned 3x3, for S-II.















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