Shape model of asteroid (130) Elektra from optical photometry and disk-resolved images from VLT/SPHERE and Nirc2/Keck

TL;DR

This study combines optical photometry and high-resolution images from VLT/SPHERE and Keck/Nirc2 to create a detailed shape model of asteroid (130) Elektra, enabling precise size and density estimates.

Contribution

The paper introduces a comprehensive shape modeling approach using all available disk-resolved images and photometry, improving size and density measurements of Elektra.

Findings

Shape model of Elektra derived with high accuracy.

Volume-equivalent diameter of 199±7 km.

Bulk density of 1.60±0.13 g/cm³.

Abstract

Asteroid (130) Elektra belongs to one of the six known triple asteroids in the main belt, so its mass has been reliably determined. We aim to use all available disk-resolved images of (130) Elektra obtained by the SPHERE instrument at VLT and by the Nirc2 of the Keck telescope together with the disk-integrated photometry to determine its shape model and its size. The volume can be then used in combination with the known mass to derive the bulk density of the primary. We apply the All-Data Asteroid Modeling (ADAM) algorithm to the optical disk-integrated data, 2 disk-resolved images obtained by the SPHERE instrument and 13 disk-resolved images from the Nirc2 of the Keck telescope, and derive the shape model and size of Elektra. We present the shape model, volume-equivalent diameter (199$\pm$7 km) and bulk density (1.60$\pm$0.13 g cm$^{-3}$) of the C-type asteroid Elektra.