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2006 SQ 372 : A Planetary Interloper from the Inner Oort Cloud. N. Kaib, A. Becker, L. Jones University of Washington. 25000 AU. a > 1,000 AU. ~. LPCs and Oort Cloud. LPCs near Earth only constrain outer Oort Cloud LPCs beyond Saturn will sample inner Oort Cloud as well. a > 20,000 AU.
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2006 SQ372: A Planetary Interloper from the Inner Oort Cloud N. Kaib, A. Becker, L. Jones University of Washington
25000 AU a > 1,000 AU ~ LPCs and Oort Cloud • LPCs near Earth only constrain outer Oort Cloud • LPCs beyond Saturn will sample inner Oort Cloud as well a > 20,000 AU
SDSS-II SN Survey Observations 2006 SQ372
SDSS-II SN Survey Observations 2006 SQ372
SDSS-II SN Survey Observations 2006 SQ372
SDSS-II SN Survey Observations 2006 SQ372
a = 796 AU q = 24.2 AU i = 19.5° Orbit Summary
Orbital Evolution Current orbit is transient - unstable after ~200 Myrs!
x semimajor axis perihelion Two Different Origin Scenarios1. Scattered Disk
x semimajor axis perihelion Two Different Origin Scenarios2. Oort Cloud OC SD
Simulations Oort Cloud • 106 particles • Orbit distributions based on Kaib & Quinn (2008) sims • Run for 1.4 Gyrs Scattered Disk • 2,500 particles • Orbit distributions based on SDO observations • Run for 4.5 Gyrs Non-symplectic variable timestep integrator based on SWIFT (Levison & Duncan, 1994; Kaib & Quinn, 2008)
Fractional Occupation Map 10° < i < 30° X 2006 SQ372
fOC/fSD Map SQ372 For 2006 SQ372: fOC/fSD 0.7
Origin Implications ProbOC/ProbSD = (fOC/fSD) x (NOC/NSD) fOC/fSD 0.7 NOC = 2 x 1011(Neslusan, 2007) NSD = 4 x 109(Fernandez, 2004) ProbOC/ProbSD > 35 ~
Origin Implications • 2006 SQ372 is at least 35 times more likely to come from the Oort Cloud compared to the Scattered Disk • Which region of the Oort Cloud?
Inner Oort Cloud Origin Semimajor axis drawdown time vs. Perihelion drift time Dq = -10 AU Ejection by Saturn Dq = 10 AU a is fixed
Inner Oort Cloud Origin Sampled by Known LPCs (~2.5%) tq ~ a-2 ta ~ 100 Myrs a < 800 AU 20 AU < q < 30 AU
Conclusions • 2006 SQ372 and 2000 OO67(Elliot et al. 2005) are first detected members of inner Oort Cloud population inside planetary region • Pan-STARRS, LSST will discover 100’s to 1000’s of similar bodies • Population statistics can provide clues about Oort Cloud and Sun’s dynamical history
SDSS Stripe 82 N S D = +1.25° 2.5° D = -1.25° 120° RA = 4hr RA = 20 hr • SDSS Supernova Survey • Sept-Nov 2005-2007 • 300 square degrees, every 2 nights • 5-band photometry • Spectroscopic followup
2006 SQ372 • 1 of 63 TNOs observed by SDSS-II SN Survey • Diameter < 100 km • Orbit: • q: 24.2 AU (between Uranus and Neptune) • a: 796 AU (largest of all TNOs) • i: 20°