Combining asteroid models derived by lightcurve inversion with asteroidal occultation silhouettes

TL;DR

This paper demonstrates how combining lightcurve inversion models with occultation data enables more accurate and unique determination of asteroid sizes and shapes, improving our understanding of asteroid physical properties.

Contribution

It introduces a method to integrate asteroid shape models with occultation observations, refining size estimates and resolving pole ambiguities.

Findings

Asteroid sizes can be measured with ~10% accuracy.

Combining models with occultation data refines shape and size estimates.

Occultations help resolve pole solution ambiguities.

Abstract

Asteroid sizes can be directly measured by observing occultations of stars by asteroids. When there are enough observations across the path of the shadow, the asteroid's projected silhouette can be reconstructed. Asteroid shape models derived from photometry by the lightcurve inversion method enable us to predict the orientation of an asteroid for the time of occultation. By scaling the shape model to fit the occultation chords, we can determine the asteroid size with a relative accuracy of typically ~ 10%. We combine shape and spin state models of 44 asteroids (14 of them are new or updated models) with the available occultation data to derive asteroid effective diameters. In many cases, occultations allow us to reject one of two possible pole solutions that were derived from photometry. We show that by combining results obtained from lightcurve inversion with occultation timings, we can obtain unique physical models of asteroids.