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M. Hammergren, B. Macintosh, S. Gibbard (LLNL-IGPP), D. Gavel (LLNL)
We present 0.05-arcsecond resolution near-IR images of the unusual main belt asteroid (216) Kleopatra, obtained via speckle interferometry with the 10-m Keck-I telescope in November 1999. The time series of 22 images cover nearly a full rotation, and clearly resolve the asteroid. The images reveal it to be a single, highly-elongated, dumbbell-shaped body, oriented about 30 degrees from pole-on during the time of our observations. We have performed Hapke photometric modeling of the asteroid's surface, and have constructed a three-dimensional shape model. The shape we have derived for this asteroid is nearly identical to the radar delay-Doppler reconstructions of Ostro et al. (Science 288, 836). While the Ostro et al. observations permit a higher spatial resolution in their modeling, our observations have the virtue of being real spatial images, thus providing independent confirmation of their shape model. Our shape model is also consistent with the stellar occultation results of Dunham (Sky and Telescope 83, 73) and pre-COSTAR HST images reported by Storrs et al. (Icarus 137, 260). Our images also allow us to search for albedo and color variations across the asteroid; no significant heterogeneity is seen.
This research was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under contract W-7405-ENG-48.
The author(s) of this abstract have provided an email address for comments about the abstract: hammer@igpp.ucllnl.org