A Celestial is an incredibly powerful alien race, responsible for the creation of Centerpoint Station, cosmic turbines, the Maw, Correlia (and other systems too), and the Hyperspace Disturbances along the galaxy's edge. They also had the power to enslave the Killiks, and force the Sharu people into primitivism. Fun fact: the three force users on Mortis were Celestials, and were millions of years old. The other guy answered the Rakatan question.