Rectified Asteroid Albedos and Diameters from IRAS and MSX

TL;DR

This study refines asteroid diameters and albedos using infrared data from IRAS and MSX, applying thermal models and new absolute magnitude data, revealing consistent beaming parameters across asteroid types.

Contribution

It introduces updated thermal modeling techniques and new absolute magnitude data to improve asteroid property estimates from infrared observations.

Findings

NEATM provides more robust diameter and albedo estimates.

Mean beaming parameter η is 1.07 ± 0.27, independent of asteroid properties.

No size-dependent rotation rate trends in η are observed.

Abstract

Rectified diameters and albedo estimates of 1517 main belt asteroid selected from the IRAS and MSX asteroid photometry catalogues are derived from updated infrared thermal models, the Standard Thermal Model (STM) and the Near Earth Asteroid Thermal Model (NEATM), and Monte Carlo simulations, using new Minor Planet Center (MPC) compilations of absolute magnitudes (H-values) constrained by occultation and radar derived parameters. The NEATM approach produces a more robust estimate of albedos and diameters, yielding albedos of $p_{v}$(NEATM mean)$=0.081 \pm 0.064$. The asteroid beaming parameter ($\eta$) for the selected asteroids has a mean value of $1.07 \pm 0.27$, and the smooth distribution of $\eta$ suggests that this parameter is independent of asteroid properties such as composition. No trends in $\eta$ due to size-dependent rotation rates are evident. Comparison of derived $\eta$'s as a function of taxonomic type indicates the beaming parameter values for S-type and C-type asteroids are identical within the standard deviation of the population of beaming parameters.