Arecibo and Goldstone radar images of near-Earth Asteroid (469896) 2005 WC1

作者：Lawrence Kenneth J^*; Benner Lance A M; Brozovic Marina; Ostro Steven J; Jao Joseph S; Giorgini Jon D; Slade Martin A; Jurgens Raymond F; Nolan Michael C; Howell Ellen S; Taylor Patrick A

来源：Icarus, 2018, 300: 12-20.

DOI：10.1016/j.icarus.2017.08.028

• Radar observations
• Near-Earth asteroids
• Asteroid rotation
• Asteroid surfaces

We report radar observations of near-Earth asteroid (469896) 2005 WC1 that were obtained at Arecibo (2380 MHz, 13 cm) and Goldstone (8560 MHz, 3.5 cm) on 2005 December 14-15 during the asteroid's approach within 0.020 au The asteroid was a strong radar target. Delay-Doppler images with resolutions as fine as 15 m/pixel were obtained with 2 samples per baud giving a correlated pixel resolution of 7.5 m. The radar images reveal an angular object with 100 m-scale surface facets, radar-dark regions, and an estimated diameter of 400 +/- 50 m. The rotation of the facets in the images gives a rotation period of similar to 2.6 h that is consistent with the estimated period of 2.582 h +/- 0.002 h from optical lightcurves reported by Miles (private communication). 2005 WC1 has a circular polarization ratio of 1.12 +/- 0.05 that is one of the highest values known, suggesting a structurally-complex near-surface at centimeter to decimeter spatial scales. It is the first asteroid known with an extremely high circular polarization ratio, relatively low optical albedo, and high radar albedo.

• 出版日期2018-1-15