Beyond the Kuiper Belt Edge: Sednoids and the Inner Oort Cloud
Abstract
The Kuiper Belt is thought to be a relic from the original protoplanetary disk. This region contains some of the least processed material in the solar system and is the suspected source of the Centaurs and short period comets. Currently there are over one thousand Kuiper Belt objects known with perihelion between about 30 and 50 AU. Only one object is known to have a perihelion significantly beyond 50 AU (Sedna at 76 AU) even though shallow surveys to date should have found many such Sednoids if the size distribution beyond this ``edge'' is similar to what has been seen elsewhere in the Kuiper Belt. The strong size and heliocentric distance dependence of the flux density of sunlight scattered from an object requires a survey to obtain very faint magnitudes in order to access the population of objects of size 100 km and less beyond 50 AU. Kuiper Belt surveys to date have not been optimized to survey beyond the Kuiper Belt edge at 50 AU as they have either covered large areas but been to shallow depths (less than 23rd mag), have gone deep but covered a very small area of sky (a few square degrees), or do not have the required cadence to detect the ultra slow moving Sednoids or inner Oort cloud objects that are well beyond 50 AU. We are performing an ultra-deep wide-field outer solar system survey with the wide-field imagers on the large class Magellan 6.5 m and Subaru 8 m telescopes to determine if the objects beyond 50 AU are fainter than expected, if there is truly a dearth of objects, or if the Kuiper Belt continues again after some sizable gap possibly caused by a planet sized object. This survey is the widest deepest survey for such distant objects ever obtained. We will constrain the origin of Sedna and determine if this eccentric, distant body is unique (as once believed for Pluto) or just the first of a new class of object in the outer Solar System.
- Publication:
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AAS/Division for Planetary Sciences Meeting Abstracts #45
- Pub Date:
- October 2013
- Bibcode:
- 2013DPS....4551104S