36th DPS Meeting, 8-12 November 2004
Session 8 Kuiper Belt II: Binaries and Dynamics
Oral, Tuesday, November 9, 2004, 8:30-10:00am, Lewis

## [8.09] Torques on Sedna by a Putative Massive Body in the Oort Cloud

J. J. Matese (University of Louisiana at Lafayette), J. J. Lissauer (NASA ARC)

Morbidelli and Levison (arXiv:astro-ph/0403358) consider various scenarios for the origin of the orbits of Sedna-like objects. The only one which they find to give satisfactory results is the passage of a low-velocity solar-mass star at about 800 AU during the early solar environment. They observe that creating extended scattered disk objects" (in which the largest orbits also have the largest q) requires a perturbation from the outside", but do not discuss the possibility that the external perturbation could come from a Jovian-mass wide-binary solar companion. We investigate the parameter space of such an object which would adiabatically detach Sedna from Neptune's dominance with qS (0) \approx 30 AU, aS = 531 AU. Demanding that the detached osculating orbit satisfy qmin>15 AU, qmax >75 AU, the companion's mass and orbit parameters (m, a, e) that can produce n osculation cycles in a time \Delta t are m/M_{Jup}\approx n t_{ss}/\Delta t( a/6000 {\rm AU})3(1-e2)3/2. A wide-binary companion could also be the source of the 7\circ misalignment of the ecliptic plane normal with the solar spin axis (Hogg, Quinlan and Tremaine 1991, Astron. J. \textbf{101(6)}, 2274), but only if n\approx 100. The solar impulse considered by Morbidelli and Levison would produce an ecliptic plane tilt only 1/100 of that observed.

{\em J.J.L. received support from Planetary Geology and Geophysics Grant 344-30-1L.}