2005 Annual Science Report
University of Hawaii, Manoa Reporting | JUL 2004 – JUN 2005
Kuiper Belt Orbital Studies
The discovery of the Kuiper Belt has dramatically changed our understanding of the outer solar system. The KBOs form several dynamical classes: the resonant population and the classical KBOs which are stable over the age of the solar system, the scattered disk objects which are unstable because of close encounters with Neptune, and the extended scattered objects. Recent work has found that there must be a sharp cut off in the mass distribution beyond 50 AU. The inner edge of the Kuiper Belt is believed to be the source of the
Centaurs, which eventually evolve into the short-period Jupiter-family comets. While only a small fraction of the total population of KBOs has been discovered, the KBOs studied to date exhibit remarkable physical diversity. The distribution of the orbital parameters of the KBOs provide a fossil record of the dynamical processes which have sculpted the outer regions of the protoplanetary disk over the age of the Solar System. Moreover, the Kuiper
Belt is believed to be the vestigial manifestation in our Solar System of the planet-forming dust disks seen around some other stars. The orbits and physical properties of Kuiper Belt Objects (KBOs) provide valuable constraints on dynamical and environmental evolution of the outer Solar System. As the population of KBOs increases, interest is now turning to the characterization of the physical properties of these objects. We are currently at the same point in our understanding of the surfaces and composition of KBOs and Centaurs as we were with the asteroid belt in the early 1970s.
However, a full understanding of this fossil record requires a large and well characterized sample of objects with accurate orbits. We are collaborating on the Deep Ecliptic Survey (Lowell, MIT, IfA, UA, UC Berkeley) which is the largest KBO survey to date. Objects discovered by the survey require addtional astrometric observation to determine accurate orbits. Eight nights on the UH2.2m telescope were used for astrometric follow up of newly discovered objects, and those for which the orbits are not well enough known for classification. All of this data has been reduced and published, and is being used in new dynamical investigations of the outer solar system small body population. This work is complementary to our program of the studies of the physical properties of these small bodies.