Oh? Which ones? You should post them there. AFAIK it's the most complete list of the real nebulae.
I've found a reference to a blue galaxy; M51 or the Whirlpool galaxy, although I haven't been able to find it's position relative to Andromeda, so I don't know if it's M51 I'm looking at.
Has this spot been observed before?
Does Stellarium provide another answer for another candidate?