Changes

== Detached Scattered Disk Objects ==

== Detached Scattered Disk Objects ==

Seven TNOs are in orbits around the [[Sun]] at perihelia greater than 40 AU and semi-major axes greater than 50 AU. These include [[Sedna]], the one named object among them. They are significantly more distant from the Sun than are other SDOs, and most astromomers consider them too far away for Neptune to have had any effect on them. For that reason, many astronomers do not consider them part of the scattered disk at all, but instead part of an "inner [[Oort cloud]]." These are the "detached" SDOs, and are a subject of great debate.<ref name=Gomes/> Some astronomers suggest that they are part of an "extended" scattered disk.<ref name=Gladman>Gladman B. "[http://www.astro.ubc.ca/people/gladman/cr105.html Evidence for an Extended Scattered Disk]?" University of British Columbia, March 31, 2001. Accessed June 21, 2008.</ref>

Seven TNOs are in orbits around the [[Sun]] at perihelia greater than 40 AU and semi-major axes greater than 50 AU. These include [[Sedna]], the one named object among them. They are significantly more distant from the Sun than are other SDOs, and most astromomers consider them too far away for Neptune to have had any effect on them. For that reason, many astronomers do not consider them part of the scattered disk at all, but instead part of an "inner [[Oort Cloud]]." These are the "detached" SDOs, and are a subject of great debate.<ref name=Gomes/> Some astronomers suggest that they are part of an "extended" scattered disk.<ref name=Gladman>Gladman B. "[http://www.astro.ubc.ca/people/gladman/cr105.html Evidence for an Extended Scattered Disk]?" University of British Columbia, March 31, 2001. Accessed June 21, 2008.</ref>

The presence of these extremely distant objects has led some astronomers to speculate that a star as massive as the sun might have come as close to the Sun as 800 AU and sent these objects into highly eccentric orbits.<ref name=Morbidelli>Morbidelli A., and Levison H. "[http://www.iop.org/EJ/abstract/1538-3881/128/5/2564/ Scenarios for the Origin of the Orbits of the Trans-Neptunian Objects 2000 CR₁₀₅ and 2003 VB₁₂ (Sedna)]." ''Astron. J.'' 128:2564-2576, 2004. {{doi|10.1086/424617}} {{arXiv|astro-ph/0403358}} Accessed June 23, 2008.</ref> Others speculate that a [[gas giant]] having the mass either of [[Neptune]] or [[Jupiter]], located much farther away, could produce the same or similar effect.<ref name=Gomes2>Gomes R.S., Matese J.J., and Lissauer J.J. "[http://adsabs.harvard.edu/abs/2006Icar..184..589G A distant planetary-mass solar companion may have produced distant detached objects]." ''Icarus'' 184(2):589-601, October 2006. {{doi|10.1016/j.icarus.2006.05.026}} Accessed June 23, 2008.</ref>

The presence of these extremely distant objects has led some astronomers to speculate that a star as massive as the sun might have come as close to the Sun as 800 AU and sent these objects into highly eccentric orbits.<ref name=Morbidelli>Morbidelli A., and Levison H. "[http://www.iop.org/EJ/abstract/1538-3881/128/5/2564/ Scenarios for the Origin of the Orbits of the Trans-Neptunian Objects 2000 CR₁₀₅ and 2003 VB₁₂ (Sedna)]." ''Astron. J.'' 128:2564-2576, 2004. {{doi|10.1086/424617}} {{arXiv|astro-ph/0403358}} Accessed June 23, 2008.</ref> Others speculate that a [[gas giant]] having the mass either of [[Neptune]] or [[Jupiter]], located much farther away, could produce the same or similar effect.<ref name=Gomes2>Gomes R.S., Matese J.J., and Lissauer J.J. "[http://adsabs.harvard.edu/abs/2006Icar..184..589G A distant planetary-mass solar companion may have produced distant detached objects]." ''Icarus'' 184(2):589-601, October 2006. {{doi|10.1016/j.icarus.2006.05.026}} Accessed June 23, 2008.</ref>