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标题：Anatomy of an Asteroid Breakup: The Case of P/2013 R3
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作者：David Jewitt ; Jessica Agarwal ; Jing Li 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2017
卷号：153
期号：5
DOI：10.3847/1538-3881/aa6a57
语种：English
出版社：American Institute of Physics
摘要：We present an analysis of new and published data on P/2013 R3, the first asteroid detected while disintegrating. Thirteen discrete components are measured in the interval between UT 2013 October 01 and 2014 February 13. We determine a mean, pair-wise velocity dispersion among these components of Δv = 0.33 ± 0.03 m s−1 and find that their separation times are staggered over an interval of ~5 months. Dust enveloping the system has, in the first observations, a cross-section of ~30 km2 but fades monotonically at a rate consistent with the action of radiation pressure sweeping. The individual components exhibit comet-like morphologies and also fade except where secondary fragmentation is accompanied by the release of additional dust. We find only upper limits to the radii of any embedded solid nuclei, typically ~100–200 m (geometric albedo 0.05 assumed). Combined, the components of P/2013 R3 would form a single spherical body with a radius of m, which is our best estimate of the size of the precursor object. The observations are consistent with rotational disruption of a weak (cohesive strength of ~50 to 100 N m−2) parent body, ~400 m in radius. Estimated radiation (YORP) spin-up times of this parent are , shorter than the collisional lifetime. If present, water ice sublimating at as little as 10−3 kg s−1 could generate a torque on the parent body rivaling the YORP torque. Under conservative assumptions about the frequency of similar disruptions, the inferred asteroid debris production rate is 103 kg s−1, which is at least 4% of the rate needed to maintain the Zodiacal Cloud.
关键词：comets: general;minor planets; asteroids: general;minor planets; asteroids: individual (P/2013 R3)