Mass and density of B-type asteroid (702) Alauda

TL;DR

This study uses adaptive optics observations to determine the mass, size, and density of asteroid (702) Alauda, revealing a small satellite and providing insights into its physical properties.

Contribution

First measurement of Alauda's mass, size, and density using adaptive optics and satellite orbit data, improving understanding of B-type asteroid composition.

Findings

Alauda has a satellite with a primary-to-secondary diameter ratio of ~56.

The satellite orbits at approximately 1227 km in 4.91 days.

Alauda's bulk density is estimated at 1570 ± 500 kg/m³.

Abstract

Observations with the adaptive optics system on the Very Large Telescope reveal that outer main belt asteroid (702) Alauda has a small satellite with primary to secondary diameter ratio of $\sim$56. The secondary revolves around the primary in 4.9143 $\pm$ 0.007 days at a distance of 1227 $\pm$ 24 km, yielding a total system mass of (6.057 $\pm$ 0.36) $\times$ 10$^{18}$ kg. Combined with an IRAS size measurement, our data yield a bulk density for this B-type asteroid of 1570 $\pm$ 500 kg~m$^{-3}$.