Fraction of contact binary Trojan asteroids

被引:38
作者
Mann, Rita K. [1 ]
Jewitt, David [1 ]
Lacerda, Pedro [1 ]
机构
[1] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA
关键词
minor planets; asteroids; solar system : general; survey;
D O I
10.1086/520328
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the results of an optical light-curve survey of 114 Jovian Trojan asteroids conducted to determine the fraction of contact binaries. Sparse sampling was used to assess the photometric range of the asteroids, and those showing the largest ranges were targeted for detailed follow-up observations. This survey led to the discovery of two Trojan asteroids, ( 17365) and ( 29314), displaying large light-curve ranges (similar to 1 mag) and long rotation periods (< 2 rotations day (-1)) consistent with a contact binary nature. The optical light curves of both asteroids are well matched by Roche binary equilibrium models. Using these binary models, we find low densities of similar to 600 and 800 kg m(-3), suggestive of porous interiors. The fraction of contact binaries is estimated to be between 6% and 10%, comparable to the fraction in the Kuiper Belt. The total binary fraction in the Trojan clouds ( including both wide and close pairs) must be higher.
引用
收藏
页码:1133 / 1144
页数:12
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