Rotation periods and shape asphericity in asteroid families based on TESS S1-S13 observations

TL;DR

This study analyzes the rotation periods and shape asphericity of 2859 asteroid family members using TESS data, revealing family-specific light curve properties, correlations with age, and shape characteristics related to spin rates.

Contribution

It provides the first comprehensive analysis of asteroid family rotation and shape distributions based on TESS observations, highlighting family-specific features and shape-spin correlations.

Findings

Older families have more spheroidal, low-amplitude asteroids.

Rotation period distributions differ between core and outskirts in some families.

Fast rotators tend to be spherical or spinning tops.

Abstract

Here we present the analysis of the distribution of rotation periods and light curve amplitudes based on 2859 family asteroids in 16 Main Belt families based on 9912 TESS asteroid light curves in the TSSYS-DR1 asteroid light curve database. We found that the distribution of the light curve properties follow a family-specific character in some asteroid families, including the Hungaria, Maria, Juno, Eos, Eucharis, and Alauda families. While in other large families, these distributions are in general very similar to each other. We confirm that older families tend to contain a larger fraction of more spheroidal, low-amplitude asteroids. We found that rotation period distributions are different in the cores and outskirts of the Flora and Maria families, while the Vesta, Eos, and Eunomia families lack this feature. We also confirm that very fast spinning asteroids are close to spherical (or spinning top shapes), and minor planets rotating slower than ~11 hour are also more spherical than asteroids in the 4--8 hour period range and this group is expected to contain the most elongated bodies.