Mutual Orbits and Masses of Kuiper Belt Binaries and Multiple Systems

Lowell Observatory, Flagstaff AZ

Investigators

Abstract

Kuiper Belt Objects (KBOs) are remnants of the swarm of primitive bodies that accreted in the outer parts of the protoplanetary nebula as the Solar System formed. They have diverse spectroscopic and dynamical properties, which may represent a coded memory of chemical and orbital processes early in the Solar System's history. Remarkably, 15% of KBOs are found orbiting about each other in binary or multiple systems. This provides a way to measure KBO masses and constrain their histories, as well as to test theories for the evolution of the protoplanetary disk. But first, the orbits themselves need to be determined. In this project, the collaborating team will carry out high-resolution imaging observations of KBO binaries, using the laser guide-star adaptive optics system on the Gemini-North telescope, roughly doubling the sample of known orbits. The observing program will obtain semi-major axes, eccentricities, periods, and spatial orientations for the orbits over the course of 3 years. From the data, constraints on object masses, shapes, and composition will be derived. The statistics of the orbital elements will constrain both the mode of binary formation and the subsequent evolution, which are tied to conditions in the protoplanetary nebula. In addition to the observational program, the proposing team will contribute to Lowell Observatory's middle-school outreach program for the Navajo and Hopi communities, and will supervise undergraduate students in research. Lowell's partnership in the Discovery Channel Telescope project will also contribute to broader public understanding of astronomy.