Observational Evidence for an Impact on the Main-belt Asteroid (596) Scheila
Observational Evidence for an Impact on the Main-belt Asteroid (596) Scheila
复制标题
主带小行星 (596) Scheila 撞击的观测证据
DOI：
10.1088/2041-8205/740/1/l11
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
他17名
中科院分区：
文献类型：
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作者：
Ishiguro;M.…;Terada;H.…;他17名
2010 年 12 月，在 (596) Scheila 周围观察到了一次意外的爆发。撞击发生后不久，我们就使用地面望远镜观测到了 (596) Scheila。 2011年2月后，我们成功探测到一条微弱的线状尾迹，为确定沙尘喷射日期提供了线索。结果发现，12月3.5±1.0日，0.1~1μm到100μm的尘埃颗粒被脉冲喷射到行星际空间中。喷射物质量估计为(1.5–4.9)× 10 8 kg，表明该事件挖掘出的质量相当于一个直径500–800 m的陨石坑。我们还发现，撞击事件后光变曲线的形状发生了变化，可能是因为撞击地点周围挖掘出了新的物质。我们得出的结论是，一颗十米大小的小行星在发现前八天与 (596) Scheila 相撞。
An unexpected outburst was observed around (596) Scheila in 2010 December. We observed (596) Scheila soon after the impact using ground-based telescopes. We succeeded in the detection of a faint linear tail after 2011 February, which provides a clue to determine the dust ejection date. It is found that the dust particles ranging from 0.1–1 μm to 100 μm were ejected into the interplanetary space impulsively on December 3.5±1.0 day. The ejecta mass was estimated to be (1.5–4.9)× 10 8 kg, suggesting that an equivalent mass of a 500–800 m diameter crater was excavated by the event. We also found that the shape of the light curve changed after the impact event probably because fresh material was excavated around the impact site. We conclude that a decameter-sized asteroid collided with (596) Scheila only eight days before the discovery.