A very deep exposure of NGC 55, a distorted edge-on spiral. The nuclear bulge is the more orange-coloured glow. There is very intense star formation with clusters of hot OB stars visible as tiny blue dots.
A mosaic of three almost totally overlapping panels, in order to fit in the frame. Aspen CG16M on 20 inch PlaneWave. Total exposure 40 hrs. Luminance: 28 hours, RGB: 4 hrs per channel, all in 30 min unbinned subs. The deep exposure has brought out the colour and form of a very large number of distant galaxies. North up. 0.55 sec arc/pixel.