Hubble Space Telescope Observations of 3200 Phaethon at Closest Approach
Hubble Space Telescope Observations of 3200 Phaethon at Closest Approach
复制标题
哈勃太空望远镜对 3200 Phaethon 最近距离观测
DOI：
10.3847/1538-3881/aae51f
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Jing Li
中科院分区：
文献类型：
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作者：
D. Jewitt;M. Mutchler;J. Agarwal;Jing Li
我们目前的哈勃太空望远镜观测活动小行星（和双子座流父）3200法厄同时，在其最接近地球（分离0.07 Au）在2017年12月。图像记录在轨道平面的0.01 °范围内，提供了对大颗粒尾迹散射引起的低表面亮度的额外灵敏度。我们将这类尾迹的视表面亮度上限定为27.2等角秒−2，对应于面内光学深度≤3 × 10−9。没有探测到比绝对星等26.3更亮的同向移动源，对应于圆当量半径1.12米（假设为0.12）。法厄同太热了，近地表的冰无法生存。我们简要地考虑了深埋冰的热力学稳定性，发现它的生存要么需要非常小的（类似风化层）热扩散率（<10−8 m2 s−1），要么是法厄同（Phaethon）出人意料地最近注入到它现在的轨道（时间尺度为106年），或者两者兼而有之。
We present Hubble Space Telescope observations of the active asteroid (and Geminid stream parent) 3200 Phaethon when at its closest approach to Earth (separation 0.07 au) in 2017 December. Images were recorded within ∼1° of the orbital plane, providing extra sensitivity to low surface brightness caused by scattering from a large-particle trail. We placed an upper limit on the apparent surface brightness of such a trail at 27.2 mag arcsecond−2, corresponding to an in-plane optical depth ≤3 × 10−9. No co-moving sources brighter than absolute magnitude 26.3, corresponding to circular equivalent radius ∼12 m (albedo 0.12 assumed), were detected. Phaethon is too hot for near-surface ice to survive. We briefly consider the thermodynamic stability of deeply buried ice, finding that its survival would require either a very small (regolith-like) thermal diffusivity (<10−8 m2 s−1), or the unexpectedly recent injection of Phaethon (timescale ≲106 years) into its present orbit, or both.
木曾彗星尘埃轨迹调查报告
DOI：
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发表时间：
2009
期刊：
Adv. Sp. Res. 43
影响因子：
--
作者：
shiguro;M.;Sarugaku;Y.;Nishihara;S.;Nakada;Y.;Nishiura;S.;Soyano;T.;Tarusawa;K.;Mukai;T.;Kwon;S.M.;Hasegawa;S.;Usui;F.;Uneo;M.
通讯作者：
M.