Rotation state, colors, and albedo of the mission-accessible tiny near-Earth asteroid 2001 QJ$_{142}$

TL;DR

This study characterizes the rotation, colors, and albedo of the tiny near-Earth asteroid 2001 QJ142, revealing it as a fast-rotating, mission-accessible E- or M-type asteroid with potential implications for space missions.

Contribution

The paper provides the first detailed physical characterization of 2001 QJ142, including its rotation period, color indices, and albedo, highlighting its classification as a fast-rotating E- or M-type asteroid.

Findings

2001 QJ142 is a C- or X-complex asteroid based on color indices.

It has a possible rotation period of about 10 minutes.

The geometric albedo is approximately 0.3, consistent with E- or M-type classification.

Abstract

Context. Characterizing mission-accessible asteroids using telescopic observations is fundamental for target-selection and planning for spacecraft missions. Near-Earth asteroids on Earth-like orbits are of particular importance for applications such as asteroid mining. Aims. 2001 QJ142 is a tiny (D $\leq$ 100 m) near-Earth asteroid on an Earth-like orbit with a semimajor axis of 1.06 au, orbital eccentricity of 0.09, and orbital inclination of 3.10$^{\circ}$. We aim to characterize 2001 QJ142 using ground-based observations with future spacecraft missions in mind. Methods. We performed visible multicolor photometry of 2001 QJ142 using the TriCCS on the Seimei 3.8 m telescope in February 2024. We also revisited the images taken with the Suprime-Cam on the Subaru 8.2 m telescope in August 2012. Results. Visible color indices of 2001 QJ142 indicate that 2001 QJ142 is a C- or X-complex asteroid. We detect a possible fast rotation with a period of about 10 min, which is consistent with a previous report. The geometric albedo of 2001 QJ142 is derived to be about 0.3 from a slope of its photometric phase curve, which is consistent with an albedo derived from thermal observations with updated physical quantities. A straightforward interpretation is that 2001 QJ142 is either an E- or M-type asteroid, although surface properties of such tiny fast-rotating asteroids are not well understood. Conclusions. We infer that 2001 QJ142 is a fast-rotating mission-accessible E- or M-type near-Earth asteroid. More characterizations of tiny asteroids are particularly important for a deeper understanding of their nature.