Technical details: Location / Date: Outside of Kopparberg, Västmanland, Sweden / 2016-August Optics: Orion Optics UK AG12 Mount: 10 Micron GM1000 HPS (Unguided) Camera: Canon EOS 100D (Modded with Baader ACF filter) Exposure: 36 x 330 seconds all shot on ISO 3200 (cumulative exposure time is 3 hours and 18 minutes) Processing: Pixinsight and Photoshop   Image details: NGC 891 (also known as Caldwell 23) is an edge-on unbarred spiral galaxy about 30 million light-years away from Earth in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. NGC 891 looks as we think the Milky Way would look like when viewed edge-on (some astronomers have even noted how similar to NGC 891 our galaxy looks as seen from the Southern Hemisphere) and in fact both galaxies are considered very similar in terms of luminosity and size; studies of the dynamics of its molecular hydrogen have also proven the likely presence of a central bar. The galaxy is a member of a small group of galaxies in the Local Supercluster, sometimes called the NGC 1023 group. Other galaxies in this group are the NGCs 925, 949, 959, 1003, 1023, and 1058, and the UGCs 1807, 1865 (DDO 19), 2014 (DDO 22), 2023 (DDO 25), 2034 (DDO 24), and 2259. (Information from Wikipedia)