Video Observations of Tiny Near-Earth Objects with Tomo-e Gozen

Abstract

We report the results of video observations of tiny (diameter less than 100 m) near-Earth objects (NEOs) with Tomo-e Gozen on the Kiso 105 cm Schmidt telescope. A rotational period of a tiny asteroid reflects its dynamical history and physical properties since smaller objects are sensitive to the YORP effect. We carried out video observations of 60 tiny NEOs at 2 fps from 2018 to 2021 and successfully derived the rotational periods and axial ratios of 32 NEOs including 13 fast rotators with rotational periods less than 60 s. The fastest rotator found during our survey is 2020 HS7 with a rotational period of 2.99 s. We statistically confirmed that there is a certain number of tiny fast rotators in the NEO population, which have been missed with any previous surveys. We have discovered that the distribution of the tiny NEOs in a diameter and rotational period (D-P) diagram is truncated around a period of 10 s. The truncation with a flat-top shape is not explained well either by a realistic tensile strength of NEOs or suppression of YORP by meteoroid impacts. We propose that the dependence of the tangential YORP effect on the rotational period potentially explains the observed pattern in the D-P diagram.

arXiv commentThis article is published in PASJ as open access, published by OUP (https://doi.org/10.1093/pasj/psac043). 27 pages, 16 figures

References in corpus (21)

• Gaia Data Release 2. Summary of the contents and survey properties
• First Results from the Catalina Real-time Transient Survey
• Understanding the Lomb-Scargle Periodogram
• ATLAS: A High-Cadence All-Sky Survey System
• astroquery: An Astronomical Web-Querying Package in Python
• Density of asteroids
• Debiased orbit and absolute-magnitude distributions for near-Earth objects
• Extreme Sensitivity of the YORP Effect to Small-Scale Topography
• A 3-dimensional model of tangential YORP
• Tangential component of the YORP effect
• Detection of a faint fast-moving near-Earth asteroid using synthetic tracking technique
• Physical Properties of Near-Earth Asteroid 2011 MD
• The Mission Accessible Near-Earth Objects Survey (MANOS): first photometric results
• Low thermal conductivity of the superfast rotator (499998) 2011 PT
• Meteoroid impacts onto asteroids: a competitor for Yarkovsky and YORP
• The Mission Accessible Near-Earth Objects Survey: Four years of photometry
• Rotation acceleration of asteroids (10115) 1992 SK, (1685) Toro, and (1620) Geographos due to the YORP effect
• Phase integral of asteroids
• On the rotation rates and axis ratios of the smallest known near-Earth asteroids---the archetypes of the Asteroid Redirect Mission targets
• Limiting behavior of asteroid obliquity and spin using a semi-analytic thermal model of the YORP effect
• Photometry and model of near-Earth asteroid 2021 DW1 from one apparition

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