David,
I dont know what eyepieces you own but with a 15mm in your 8"/f6 dob giving about 80X you would not be able to separate the double star. If your keen, try it using about 150X (or a little more) in your 8". The double h 5085, is the bright star about 7' west of the core. The secondary is a very small white/blue star sitting right on the primary.
BTW, I don't care what anyone says, it still looks like a butterfly to me
CS- John B