NGC 404


3rd December 2004
Object name: NGC 404
Popular name: Mirach's ghost
Object type: Galaxy
Magnitude: 10.0
Size: 3.5'x3.5'
Apparent RA: 1h 9m 43s Apparent Dec: +35 44' 51"
Constellation: Andromeda

200mm F5 newtonian @F5 , SC3.5 toucam RAW mode. IRB +RGB filter.

Exposures. 150x5.5s and 200x1.5s luminesance. 40x10s each for RGB with colour filters.

Mirach's ghost is, in itself, not a very interesting galaxy. A small plain looking E-S0 type galaxy. However, its postion about 7 arc minutes from the 2nd magnitude M0 star beta And - known as Mirach - makes it into an interesting photographic target.

All the AVIs were stacked in Registax 3 with darkframe subtracted and "dark pixels" removed with registax 3 Sigma Clipping.

The RGB composite was produced in photoshop, and then then multiple L layers, mixing the shorter exposures and longer exposures used to produce the final image. Slight noise reduction in Neat Image.

I have gone for an "arty" result instead of a accurate one - I've over desaturated the core of Mirach so the attractive diffraction spikes run to the core. Observant readers will notice that the left spike is less well defined than the right hand spike - this is due to tiny errors in collimation - it is very difficult to be perfect with such long spikes!

Also, I am still right at the bottom of the learning curve on using RGB filters. After some study I have found my filters DO block IR - so I used the colour filters without the RGB filters for this image. This made the red channel stronger and less noisey than previous images. Also, even more careful alignment of layers may result in better starshapes.