Quantifying the bulk density of southern delta aquariid meteoroids: insights from the Canadian automated meteor observatory

Abstract

ABSTRACT Physical properties of ten millimetre-sized meteoroids from the Southern Delta Aquariids (SDA) shower are derived using optical observations from the Canadian Automated Meteor Observatory between 2020 and 2023. The meteors are found to ablate in two distinct erosion stages, the second stage showing a single, bright leading fragment. Our modelling interprets these observations as evidence for equal masses of compact grains embedded in a porous, low density matrix. The average bulk density of SDA meteors is found to be 1420 ± 100  $\rm {kg \ m^{-3}}$, with the compact component having a density of 2310 ± 160 $\rm {kg \ m^{-3}}$ and the porous component a density of 700 ± 110  $\rm {kg \ m^{-3}}$. The high bulk density of SDA meteors is comparable to densities found for the Quadrantid and Geminid showers, both of which also have low perihelion distances. This suggests that thermal desorption may play a significant role in the processing of meteoroids.