NOAO >   Observing Info >   Approved Programs >   2003A-0227

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Proposal Information for 2003A-0227


PI: Douglas Welch, McMaster University, WELCH@physics.mcmaster.ca
Address: Physics Department, 1280 Main St W, Hamilton, ON L8S 4M1, CANADA

CoI: Steve Bickerton, McMaster University
CoI: JJ Kavelaars, Dominion Astrophysical Observatory

Title: Detection of Low-Mass Kuiper-Belt Objects by Stellar Occultations using WIYN/Hydra

Abstract: We will provide the first detections of low-mass Kuiper Belt Objects by making novel use of the WIYN/Hydra system as a multi-object, high- speed photometer to record the brief occultations of background stars caused by these otherwise undetectable outer solar system bodies. The size distribution of material in the Kuiper belt holds a number of clues to the past evolution of our solar system. From the orbital distribution of large material in the belt it is apparent that some process dynamically excited the forming belt. This excitation would have truncated the size evolution of the belt, raising the random velocities of encounters to a point where only fragmentary encounters are possible. However, the measured size distribution of the large material in the belt is much steeper than an equilibrium distribution. This indicates that the disruptive process in the belt likely occurred before equilibrium was attained. Simulation of the evolution of the size distribution indicates that the turning point, or knee, in the distribution could establish the time of the ancient excitation process(es). No useful observational detections or limits exist for bodies smaller than about 7 km. The proposed work will likely provide detections for objects as small as 0.2 km, a size regime where the collisional history will reveal itself in the frequency of such objects.


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