Péridier Library Abstract Archive

Abstract No. UT 336

Title: The Discovery of Halley-sized Kuiper Belt Objects Using HST
Author(s): Anita L. Cochran (U. Texas), Harold F. Levison, S. Alan Stern (SwRI), Martin J. Duncan (Queen's U.)
Keywords: comets: general -- solar system: formation -- solar system: general
E-Mail: Anita L. Cochran (but see LANL) (to request a full copy of this paper)
Preprint: 9509100 Document source or PostScript
Release date: 10/11/95 11:04:09
Publication status: in Press (to appear in 10 December 1995 Ap.J.)
Comments: 14 pages, 3 figures

We report the statistical detection (at the >99% confidence level) of a population of 28th magnitude objects exhibiting proper motions of ~ 1 arcsecond per hour at quadrature in deep HST/WFPC2 images. The drift directions imply a preponderance of objects on prograde orbits concentrated near the ecliptic plane. We interpret this as the detection of objects which reside in the Kuiper belt near or beyond the orbit of Neptune, comparable in size to comet 1P/Halley (radii ~ 10 km for an albedo of 4%). Our observations imply a population of ~ 2.5 x 10⁴ objects deg^-2 with V < 28.6. This must be viewed as a lower limit until our search of parameter space is complete. Our observations imply that there are > 2 x 10⁸ objects of this size in the Kuiper belt with inclinations < 12 degrees and within ~ 40 AU of the Sun.