A revised asteroid polarization-albedo relationship using WISE/NEOWISE data

TL;DR

This study reanalyzes asteroid albedo and polarization data using WISE/NEOWISE, establishing a three-dimensional linear relationship and highlighting taxonomic distinctions, while noting sampling biases.

Contribution

It introduces a new three-dimensional model for asteroid polarization-albedo relationships and defines a novel parameter p* for maximal polarization variation.

Findings

The best fit is a 3D linear relation in log space.

Certain asteroid types (E, B, M) stand out in the space.

Low albedo and small asteroids are underrepresented.

Abstract

We present a reanalysis of the relationship between asteroid albedo and polarization properties using the albedos derived from the Wide-field Infrared Survey Explorer. We find that the function that best describes this relation is a three-dimensional linear fit in the space of log(albedo)-log(polarization slope)-log(minimum polarization). When projected to two dimensions the parameters of the fit are consistent with those found in previous work. We also define p* as the quantity of maximal polarization variation when compared with albedo and present the best fitting albedo-p* relation. Some asteroid taxonomic types stand out in this three-dimensional space, notably the E, B, and M Tholen types, while others cluster in clumps coincident with the S- and C-complex bodies. We note that both low albedo and small (D<30 km) asteroids are under-represented in the polarimetric sample, and we encourage future polarimetric surveys to focus on these bodies.