论文标题
小行星（3200）Phaethon的质量脱落活动通过旋转增强
Mass shedding activities of Asteroid (3200) Phaethon enhanced by its rotation
论文作者
论文摘要
小行星（3200）phaethon是B型小行星，在其围栏通道中一直活跃。该小行星被认为是双子流星流的来源。据报道，该小行星在旋转期间旋转$ 3.60 \ hr $，并且具有平均赤道直径为6.25美元\ km $的赤道直径的最高形状（带有赤道脊的扁体）。在这里，我们报告说，当散装密度为$ 0.5 \ - \ 1.5 \ {g/cm^3} $时，Phaethon的旋转状态可能接近或高于其关键旋转周期（B型小行星的典型散装密度）。我们发现，在这种情况下，除非有粘性强度为$ {\ sim} 50 \ pa \ - \ \ {\ sim} 260 \ pa $，否则Phaethon的结构对失败敏感。该结果意味着，如果有某些表面过程，例如，例如热浪，可能会发生大尺度变形并导致质量脱落。从这种解释中，我们提出了过去产生双子流星流的过程，以及最近的尘埃尾巴。 Phaethon最初在旋转周期短于当前时期。在此阶段，结构变形的大小高于目前的自旋条件，并且发生了大量的质量脱落事件，即双子流星流。经过此变形过程后，身体变得更加植入，并且旋转速度降低了。在这一点上，虽然旋转足够高，足以使身体有大量脱落事件，但这些事件的大小变小。
Asteroid (3200) Phaethon, a B-type asteroid, has been active during its perihelion passages. This asteroid is considered to be a source of the Geminid meteor stream. It is reported that this asteroid is spinning at a rotation period of $3.60 \ hr$ and has a top shape (an oblate body with an equatorial ridge) with a mean equatorial diameter of $6.25 \ km$. Here, we report that Phaethon's rotation state may be close to or above its critical rotation period when the bulk density is $0.5 \ - \ 1.5 \ {g/cm^3}$ (a typical bulk density of a B-type asteroid). We found that in this condition, the structure of Phaethon is sensitive to failure unless the cohesive strength is ${\sim}50 \ Pa \ - \ {\sim}260 \ Pa$. This result implies that if there are some surface processes driven by, for example, thermal waves, large-scaled deformation may happen and cause mass shedding. From this interpretation, we propose the processes that produced the Geminid meteor stream in the past and dust tails recently. Phaethon initially rotated at a spin period shorter than the current period. The magnitude of structural deformation at this stage was higher than the present spin condition, and a large mass shedding event, i.e., the Geminid meteor stream, occurred. After this deformation process, the body became more oblate, and its spin slowed down. At this point, while the spin was high enough for the body to have mass shedding events, the magnitude of these events became small.
