The outer and larger of the two satellites was discovered January 26, 2005, and formally designated S/2005 (2003 EL61) 1, though nicknamed "Rudolph" by the Caltech team.
O máis exterior e grande dos dous satélites foi descuberto o 26 de xaneiro de 2005, e formalmente designado S/2005 (2003 EL61) 1, e co alcume de Rudolph polo equipo do Caltech.