This is a globular star cluster called Messier 13. It's built from a stack of just 3 frames taken in bright moonlight at the end of a session with Messier 51. The moonlight washed out any guiding stars after these 3 frames and put and end to the session.

The bright star to the bottom right is Zeta Herculis, a primary star forming the constellation Hercules. It is a multiple star system of 2, and possibly 3 stars. It is little studied.