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S.J. Bickerton (McMaster University), JJ Kavelaars (Herzberg Institute of Astrophysics), D.L. Welch (McMaster University)
The smallest Kuiper Belt Object (KBO) observed to date was found at a magnitude of V=27 and is estimated to have a diameter of 10km. However, for practical reasons, the prospects of pushing significantly beyond this limit are, in a word, dim.
The structure of the size distribution of KBOs is believed to be influenced by the competing processes of accretion and collisional fragmentation. Thus, it remains an important 'observable', though an unobservable one.
We are currently working to observe the fainter KBOs indirectly through the method of stellar occultation.
We have simulated light curves of occultation events incorporating diffraction effects into the structure of the occultation 'shadow' and used these to estimate the probability and detectibility of such events. To best represent real data; light curves were made to simulate visible light (400nm -- 700nm) rather than monochromatic light. Our work suggests that occultations may be significantly more detectible than would be expected based on a purely geometric analysis which ignored the effects of diffraction. Luminosity changes caused by the 'ringing' in the diffraction pattern are detectible when the occulting KBO passes the background star within a distance of ~5 times the KBO diameter. That is to say, the 'diffraction shadow' is significantly larger than the corresponding 'geometric shadow'.
We have also designed and built a high-speed CCD camera mounted on the 72" Plaskett telescope at the Dominion Astrophysical Observatory (DAO) to be used to search for KBO occultations.
These aspects of our work will be presented. That is all, you may go now.
The author(s) of this abstract have provided an email address for comments about the abstract: bick@physics.mcmaster.ca
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Bulletin of the American Astronomical Society, 36 #4
© 2004. The American Astronomical Soceity.