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Wednesday, February 24, 2010

IC 443 finalized

A cosmic A-Bomb

I named this image of IC 443 to a "Cosmic A-Bomb" since it looks like a gigant explosion. In fact, it is a remnant of a gigant nuclear explosion, Supernova.

Nebula in natural color. Narrowband channels are mixed to match visible spectrum. Red=80% H-alpha+20% S-II, Green=O-III and Blue=80% O-III+20% H-alpha to compensate otherwise missing H-beta.

Nebula in HST-palette, Red=S-II, Green=H-a and Blue=O-III

Generally this was on of the moust difficult object to shot in longer focal lenght. Surface brightness is very low and there is extremely faint nebulosity around a main object. I wanted to show it and a detailed filaments of the supernova remnant main body. The actual remnant is much large, than my limited field of view can show.
An older wide field image of the IC 443 from a Spring season 2009.
-H-alpha 8x1200s binned 1x1
-S-II 4x600s binned 2x2
-O-III 5x600s binned 2x2
Optics: Tokina 300mm TX f2.8 @ f2.8
Camera: QHY9 @ -50 C
Guiding: Lx200 GPS 12" + LQHY5 and PHD-Guiding

I think, this was as hard object as a Sh2-240 (Simeis 147), Supernova remnant in Taurus. I shot it in last Spring season;

I found out, that color, in my older wide field image, is very usable for this new closeup version! There is not much details in very dim O-III and S-II channels- I use a method of mine, Tone Mapping, to make a color composition from images with a very different scale. It works just fine!

H-alpha channel after a Eleven hours of exposures.

Technical details:

Telescope, Meade LX200 GPS 12" @ f5
Camera, QHY9
Guiding, SXV-AO @ 7Hz
Image Scale, 0,75 arcseconds/pixel
H-alpha 18x1200s, binned 1x1 + 14 x 1200s, binned 2x2, Flats. Bias and Darks
Total exposuretime for H-alpha is about eleven hours.
Note, colors in this image are shot with a different optical configuration, back in Spring 2009, details are in a text above.

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