Choosing the best camera for astrophotography would be easy if money was no object, but unfortunately for many of us this isn’t the case. If you are just starting out in photography and find astrophotography interesting you can get started with some relatively inexpensive cameras.
Just starting out in Astrophotography and on a budget try any of the following.
Canon T3I, T4I, T5I are all great crop censor cameras that can take some nice astrophotos
Nikon D3200 is a reasonably priced camera to get you started taking some amazing photos
Canon 6d in my opinion is the astrophotography camera with the most bang for the buck.
Nikon Makes the 600d that is a great deal for what you get
Nikons’s D7100 is also worth looking into also and is a big megapixel camera with some amazing astrophotography results.