In the November 2013 edition of Sky and Telescope magazine, Alan Whitman mapped out structures within Andromeda that he has observed with his 16-inch Newtonian and a colleague had observed with a 12.5 inch Newtonian scope.
Whitman A. Going Deep: Exploring Messier 31. Sky and Telescope 2013; Nov: 58-61.
Newtonians are famous for being able to grab lots of light and resolve at high magnitude but long exposure astrophotography gives you a chance to catch up. The first page of the article is a black and white photographic negative of Andromeda that has been labelled with all the globular clusters (G designation), open clusters (C designation) and stellar associations (young, star-forming regions, A designation) that the pair have observed over many years.
I have used their map to construct my own based on my 115 minute integration with just a 71mm scope and have labelled everything that I could match on their map with my own.
These black and white negative “plates” are interesting because this is how Astronomers in the 1920s, such as Edwin Hubble explored the Cosmos. One of Hubble’s smartest moves was to hire the best photo technician and developer that he could get so that his plates were of the highest quality.
I will post my full map as soon as it is complete but here is a close up for now:
G = globular cluster (located immediately to left of letter “G”).
C = open cluster(s) (located immediately above or below letter “C” OR circled if close together).
A = stellar association (circled).
I am just amazed that I can locate globular clusters around a galaxy 2.5 million light years away with a 71mm scope in my back garden!