. ▁It ▁was ▁discovered ▁on ▁ 1 ▁November ▁ 2 0 1 0 , ▁by ▁the ▁Pan - ST AR RS ▁ 1 ▁survey ▁at ▁H ale ak ala ▁Observ atory , ▁Hawai i , ▁United ▁States . ▁The ▁" likely " ▁d war f ▁planet ▁has ▁a ▁rotation ▁period ▁of ▁ 7 . 6 ▁hours . ▁It ▁was ▁number ed ▁in ▁September ▁ 2 0 1 8 ▁and ▁remains ▁un named . ▁ ▁Or bit ▁and ▁classification ▁▁ ▁Loc ated ▁beyond ▁the ▁orbit ▁of ▁Ne pt une , ▁ ▁is ▁a ▁non - res on ant ▁classical ▁K ui per ▁bel t ▁object ▁( c ub ew ano ) ▁of ▁the ▁so - called ▁hot ▁population , ▁which ▁have ▁higher ▁incl in ations ▁than ▁those ▁of ▁the ▁cold ▁population . ▁According ▁to ▁Michael ▁Brown ▁it ▁is ▁a ▁" likely " ▁d war f ▁planet . ▁It ▁or bits ▁the ▁Sun ▁at ▁a ▁distance ▁of ▁ 3 8 . 0 – 4 8 . 1   AU ▁once ▁every ▁ 2 8 2 ▁years ▁and ▁ 2 ▁months ▁( 1 0 3 , 0 6 0 ▁days ; ▁semi - major ▁axis ▁of ▁ 4 3 . 0 2   AU ). ▁Its ▁orbit ▁has ▁an ▁ecc ent ric ity ▁of ▁ 0 . 1 2 ▁and ▁an ▁incl ination ▁of ▁ 2 9 ° ▁with ▁respect ▁to ▁the ▁e cli ptic . ▁The ▁body ' s ▁observation ▁arc ▁begins ▁with ▁its ▁official ▁discovery ▁observation ▁at ▁H ale ak ala ▁in ▁November ▁