People who fly into space in magic bubbles and land on random planets. When they get to the planets they begin to have intimate relationships with the stars. Cussing at them, falling in love with them, having sex with them, spilling out the most intimate details of their heart to them. Soon all the stars know the secrets that most people save for their diaries and therapists. And these people, they are Starfuckers.
Oh, and the greatest band ever.
I think the definition of Starfucker pretty much is the example.