In September 10, 2005, a month after Eris' discovery, its moon was discovered by the adaptive optics team at the Keck telescopes in Hawaii, who was carrying out observations of the four brightest Kuiper belt objects. In addition to its provisional designation , its discoverers (among them Michael E. Brown), informally nicknamed it "Gabrielle", while Eris was nicknamed "Xena". In 2006, the International Astronomical Union has instead given its official name, Dysnomia, which retains a reference to "Xena", as the English translation of Dysnomia, "Lawless", echoes the name of actress Lucy Lawless.