NGC891



Object name: NGC 891
Object type: Galaxy
Magnitude: 10.1
Size: 11.7'x1.6'
Position angle: 22°
Apparent RA: 2h 22m 52s Apparent Dec: +42° 22' 24"
Constellation: Andromeda

200mm F5 newtonian @F5 , SC3.5 toucam RAW mode. IRB + RGB filters.
80mm F5 refractor @ F10 guidescope with SC1 toucam and GuideDog

Exposures. 200x10s and 150x3s luminescence. 40x15s each with RGB filters.

A very popular edge on galaxy in Andromeda. This was one of the first objects I pointed my SC3 camera at on my first light evening last month. I've revisited it with colour filters and better tracking.

Whilst imaging, NGC891 was almost directly overhead - see this image for the scope in action on this target. (Time to repaint those counterweights again)

The AVIs were stacked in Registax 3 with darkframe subtracted and "dark pixels" removed with Registax 3 Sigma Clipping. Curves in photoshop. RGB layers combined, mutiple L layerings and final saturation reduction in photoshop. Slight noise reduction in Neat Image

I'm quite pleased with the final results, although some of the "minty green" stars could be improved. There is also some low level non-random noise. This has something to do with the RAW settings and the "optical black", or so I'm told. Its been exaggerated by temporarily resizing the image 2x in photoshop during the RGB alignment phase to get a more accurate matching.

Feb 2005

Dreadful weather of late, so I have been re-processing some of my RGB shots using IRIS to register and balance to the colour channels. Below is a different result....