Spectral and spin measurement of two small and fast-rotating near-Earth asteroids
In May 2012 two asteroids made near-miss "grazing" passes at distances of a few Earth-radii: 2012 KP24 passed at 9 Earth-radii and 2012 KT42 at only 3 Earth-radii. The latter passed inside the orbital distance of geosynchronous satellites. From spectral and imaging measurements using NASA&...
Main Authors: | , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Elsevier B.V.,
2014-03-06T20:56:49Z.
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Subjects: | |
Online Access: | Get fulltext |
Summary: | In May 2012 two asteroids made near-miss "grazing" passes at distances of a few Earth-radii: 2012 KP24 passed at 9 Earth-radii and 2012 KT42 at only 3 Earth-radii. The latter passed inside the orbital distance of geosynchronous satellites. From spectral and imaging measurements using NASA's 3-m Infrared Telescope Facility (IRTF), we deduce taxonomic, rotational, and physical properties. Their spectral characteristics are somewhat atypical among near-Earth asteroids: C-complex for 2012 KP24 and B-type for 2012 KT42, from which we interpret the albedos of both asteroids to be between 0.10 and 0.15 and maximum effective diameters of 20 ± 6 and 6 ± 1 m, respectively. Among B-type asteroids, the spectrum of 2012 KT42 is most similar to 3200 Phaethon and 4015 Wilson-Harrington. Not only are these among the smallest asteroids spectrally measured, we also find they are among the fastest-spinning: 2012 KP24 completes a rotation in 2.5008 ± 0.0006 min and 2012 KT42 rotates in 3.634 ± 0.001 min. United States. National Aeronautics and Space Administration (NASA near-Earth object observation Program, Grant NNX10AG27G) |
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