Beyond the Edge of the Solar System: Sedna, 2012 VP113 and the Inner Oort Cloud

Thursday, 03 April 2014 9 a.m. — 10 a.m. MST

AURA Lecture Hall

NOIRLab South Colloquia
CHAD TRUJILLO (Gemini North, Hilo, Hawaii and Gemini South Visiting Astronomer)

Our solar system shows a sharp drop in minor planets beyond the Kuiper Belt, an edge which ends at about 50 AU from the Sun.  Only two objects have ever been found with perihelion (closest approach to the sun) farther away than this edge.  The first was Sedna, discovered over a decade ago, and the second is 2012 VP113 (nicknamed "Biden"), discovered with DECam at CTIO and announced last week.  These two dwarf planets are the first members of the inner Oort cloud whose population could outnumber all stable small body reservoirs in the solar system.  The mechanism of formation for the inner Oort cloud bodies is widely debated, but all scenarios provide unusual insights into our solar system's formation.  One of the most peculiar observations of the inner Oort cloud bodies is a clustering of the poorly studied orbital parameter "argument of perihelion", which could be explained by presence of an as-yet undiscovered super-Earth body located beyond 250 AU.  I will describe the discovery of 2012 VP113 and some of the exciting future prospects the inner Oort cloud bodies suggest for discoveries beyond the observable edge of our solar system.