Spin Parameters and Shape Models of Near-Earth Asteroids (4660) Nereus, (21088) Chelyabinsk, (66146) 1998 TU3, and (297418) 2000 SP43

TL;DR

This study characterizes the shapes and spin parameters of four near-Earth asteroids using new and archival light-curve data, revealing potential YORP effect on one asteroid.

Contribution

It provides new shape and rotational models for four NEAs and reports a possible YORP acceleration for (66146) 1998 TU3, enhancing understanding of asteroid spin dynamics.

Findings

Derived shape models and spin parameters for four NEAs.

Confirmed consistent rotation periods with previous studies.

Detected possible YORP acceleration on (66146) 1998 TU3.

Abstract

We present our shape and rotational characterization of four near-Earth asteroids observed as part of the Visible NEAs Observations Survey. This work includes 61 new light curves obtained between 2020 June and 2024 September for asteroids (21088) Chelyabinsk and (66146) 1998 TU3 and the potentially hazardous asteroids (4660) Nereus and (297418) 2000 SP43. We combine these observations with archival data to derive their shape models, spin parameters, and refined rotation periods using a light-curve inversion method. Our derived rotational periods are consistent with previously published values for all the objects. We present constant-period models for each asteroid, while for (66146) 1998 TU3 we detect a possible Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) acceleration of $\upsilon \simeq 2.05 \times 10^{-8} \text{ rad day}^{-2}$, potentially adding it to the short list of asteroids known to experience the YORP effect.