Precise astrometry and diameters of asteroids from occultations -- a data-set of observations and their interpretation

TL;DR

This paper presents a comprehensive, regularly updated data-set of over 5,000 asteroid occultation observations, including precise astrometry, diameters, shape models, and satellite information, enhancing asteroid characterization.

Contribution

The paper introduces a new, extensive data-set of asteroid occultations with high-precision measurements and compares these diameters with satellite data for improved accuracy.

Findings

The data-set includes over 5,000 occultation observations with 1 mas astrometry.

Comparison shows satellite diameters are best combined for accuracy.

The data-set is publicly available at NASA's Planetary Data System.

Abstract

Occultations of stars by asteroids have been observed since 1961, increasing from a very small number to now over 500 annually. We have created and regularly maintain a growing data-set of more than 5,000 observed asteroidal occultations. The data-set includes: the raw observations; astrometry at the 1 mas level based on centre of mass or figure (not illumination); where possible the asteroid's diameter to 5 km or better, and fits to shape models; the separation and diameters of asteroidal satellites; and double star discoveries with typical separations being in the tens of mas or less. The data-set is published at NASA's Planetary Data System and is regularly updated. We provide here an overview of the data-set, discuss the issues associated with determining the astrometry and diameters, and give examples of what can be derived from the data-set. We also compare the occultation diameters of asteroids with the diameters measured by the satellites NEOWISE, AKARI AcuA, and IRAS, and show that the best satellite-determined diameter is a combination of the diameters from all three satellites.