Chadwick A. "Chad" Trujillo (born November 22, 1973) is an astronomer and the co-discoverer of the dwarf planet Eris.Trujillo works with computer software and has examined the orbits of the numerous trans-Neptunian objects (TNOs), which is the outer area of the solar system that he specialized in. In late August 2005, it was announced that Trujillo, along with Michael E. Brown and David L. Rabinowitz, had discovered Eris.