Dragon's Egg is a 1980 hard science fiction novel byRobert L. Forward.
It is a first contact story about humans meeting theCheela, a race of beings who live on the surface of a neutron star. Both races live at a different time frame - twenty-nine seconds for a human is the rough equivalent of a year for a Cheela. Was followed by a sequel,Starquake.
Notable as a hard science fiction story in that the science tends to be the focus.