Pegasus contains a number of galaxy groups and clusters. NGC 7331, the large spiral top right in my image, makes up part of the 'deer lick' group, and is accompanied by four prominent 'fleas' (at least on plate-solving). In my parlance these might be considered the 'salt lick with infamous Scottish midges' (which are fortunately much further away)!
NGC 7813 and friends make up the more famous 'Stephan's quintet' - centre left in my image - a remote cluster some 290 mLY away, apart from NGC 7320 (top left), which is much closer (at 40 mLY line of sight). NGC 7318 A/B (in the middle) are interesting, in that 7318 B has 'fallen in' to the cluster... at several millions of mph, creating a huge sonic boom [Wikipedia]. HST has taken some amazing images of these interactions, and the resulting galactic wreckage [
https://www.nasa.gov/mission_pages/hubble/multimedia/ero/ero_stephan_quintet.html]
Anyway, closer to home, I am quite pleased with this image, given my optical train was badly set up resulting in excessive vignetting, and sky conditions were far from perfect. Captured and stacked, with auto-dark frame subtraction in Envisage, and then aligned in Nebulosity. Post-processing with heavy HDR and devonvolution, in Startools, helped bring out the detail in these galaxy groups. On a night of steady seeing, I would like to try these at f10, to bring out more detail in each group.
Comments