Explaining the origin of the orbit of 2000 CR _ { 105 } ( a \sim 230 AU , q \sim 45 AU ) is a major test for our understanding of the primordial evolution of the outer Solar System . Gladman et al . ( 2001 ) showed that this objects could not have been a normal member of the scattered disk that had its perihelion distance increased by chaotic diffusion . In this paper we explore four seemingly promising mechanisms for explaining the origin of the orbit of this peculiar object : ( i ) the passage of Neptune through a high-eccentricity phase , ( ii ) the past existence of massive planetary embryos in the Kuiper belt or the scattered disk , ( iii ) the presence of a massive trans-Neptunian disk at early epochs which exerted tides on scattered disk objects , and ( iv ) encounters with other stars . Of all these mechanisms , the only one giving satisfactory results is the passage of a star . Indeed , our simulations show that the passage of a solar mass star at about 800 AU only perturbs objects with semi-major axes larger than roughly 200 AU to large perihelion distances . This is in good agreement with the fact that 2000 CR _ { 105 } has a semi-major axis of 230 AU and no other bodies with similar perihelion distances but smaller semi-major axes have yet been discovered . The discovery of 2003 VB _ { 12 } , ( a = 450 AU , q = 75 AU ) announced a few days before the submission of this paper , strengthen our conclusions .