Uncertainties on asteroid albedos determined by thermal modeling

Abstract

We present an analysis of the accuracy of geometric albedos determined for asteroids through the modeling of observed thermal infrared radiation. We show that albedo uncertainty is dominated by the uncertainty on the measured HV absolute magnitude, and that any analysis using albedos in a statistical application will also be dominated by this source of uncertainty. For all but the small fraction of asteroids with a large amount of characterization data, improved knowledge of the HV magnitude will be fundamentally limited by incomplete phase-curve coverage, incomplete light-curve knowledge, and the necessary conversion from the observed band to the V band. Switching the absolute magnitude standard to a different band such a r¢ would mitigate the uncertainty due to band conversion for many surveys, but this only represents a small component of the total uncertainty. Therefore, techniques making use of these albedos must ensure that their uncertainties are properly accounted for.