Resolve the rotational state of asteroid 2021 PS2

Determine whether near-Earth asteroid 2021 PS2 is tumbling, an asynchronous binary, or affected by aliasing or noise by collecting additional photometric data sufficient to resolve its individual rotational periods.

Background

The one-hour observing session for 2021 PS2 produced a tentative period near 0.27 hours and a second phenomenological fit with periods near 0.28 and 1.11 hours. The low periodogram significance and limited temporal coverage prevent a secure interpretation.

The authors identify tumbling and an asynchronous binary system as alternative explanations, while also acknowledging aliasing and noise. Additional observations are explicitly required to determine which interpretation is correct.

References

This can indicate that the asteroid is tumbling, although, given the limited data coverage, it is not possible to determine its individual values. An alternative scenario is a binary system with different periods for each component, but unfortunately, as for NEA 2024~WB, the data cannot distinguish among binarity, tumbling, aliasing, or noise. More photometric data will be necessary for this target.

— Photometric characterization of near-Earth asteroids: rotation, taxonomy, and candidate evidence for internal cohesion  (2609.02563 - Carbognani et al., 2 Sep 2026) in Appendix, subsection “(618350) 2021 PS$_2$”