NGC 891 is an edge-on spiral galaxy about 30 million light years from Earth in the constellation Andromeda. It was discovered by William Herschel in 1784. It is commonly classed as an unbarred spiral galaxy but studies of the dynamics of molecular hydrogen indicate the presence of a bar. It is considered to be very similar to the Milky Way and to look very much the way that the Milky Way would appear if viewed edge-on [1].
In addition to NGC 891, there are around another 20 galaxies in the background. It's fun to try to find them but it's easier in the starless image (B). This was created using StarXTerminator, which distinguishes between stars and background galaxies quite accurately.
This image was one of the first that I requested on Roboscope's Pier 3; I wanted to look at the performance of the fast Newtonian, hence the two sets of subs. There were also luminance subs but I found that they degraded the image. Despite the short integration time the image is better than my earlier one, taken from the west of Ireland with the 8" RC. Partly, this will be the better skies in Spain and the better light gathering of the ASA but some is the impact of Russel Croman's Noise, Star and Blur Xterminators. These really are game changers.
CS
[1]
https://en.wikipedia.org/wiki/NGC_891
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