Quote:
Originally Posted by Jemmo
So what magnitude objects would be relatively easy for a nooby to find with my f5 10" dobsonian. Would mag 12 be easy enough
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Magnitudes for DSOs are what are called integrated magnitudes. In other words they are an estimate of how bright a point source would be if it all the light from the extended object (the DSO) was concentrated in it. This is why you often hear observers talk about surface brightness. A mag 12 star is easy in a 10" scope, a mag 12 galaxy where the light may be spread over and area 5' x 2' is harder, a mag 12 nebula spread over 1 square degree of space is very faint and hard to pick up if there are no bright patches.
Malcolm