NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos

TL;DR

This paper reports preliminary measurements of asteroid sizes and reflectivities from the first year of the NEOWISE Reactivation mission, including many objects previously uncharacterized, with accuracy estimates provided.

Contribution

It provides the first large-scale dataset of asteroid diameters and albedos from NEOWISE Reactivation, including new objects and improved measurement techniques.

Findings

Detected 7,959 asteroids in the first year

Approximately 17% of these are newly characterized

Diameters are accurate within ~20%, albedos within ~40% with good data

Abstract

We present preliminary diameters and albedos for 7,959 asteroids detected in the first year of the NEOWISE Reactivation mission. 201 are near-Earth asteroids (NEAs). 7,758 are Main Belt or Mars-crossing asteroids. 17% of these objects have not been previously characterized using WISE or NEOWISE thermal measurements. Diameters are determined to an accuracy of ~20% or better. If good-quality H magnitudes are available, albedos can be determined to within ~40% or better.