The rotational light curve of (79360) Sila–Nunam, an eclipsing binary in the Kuiper Belt
The rotational light curve of (79360) Sila–Nunam, an eclipsing binary in the Kuiper Belt
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(79360) Sila-Nunam（柯伊伯带食双星）的旋转光变曲线
DOI：
10.1016/j.icarus.2014.03.046
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发表时间：
2014
期刊：
影响因子：
3.2
通讯作者：
A. Verbiscer
中科院分区：
文献类型：
--
作者：
David L. Rabinowitz;S. Benecchi;W. Grundy;A. Verbiscer
我们结合多个带通中的长期光度观测，确定了双星柯伊伯带天体(79360)Sila-Nunam的旋光曲线。我们测量到一个明确的基本周期为6.2562°±0.0.002°d，在早先由HST观测解算双星所确定的轨道周期(PORB=0.12.50995°±0.0.00036°d)的0.02%内。光曲线呈双峰型，并由两个正弦曲线之和很好地拟合：初级正弦曲线周期为Porb/2，峰峰值幅度为0.120±0.012 mAg，次要正弦曲线周期为Porband峰峰幅度0.044±0.010 mAg。剔除∼0.1度内的观测，我们测量了线性太阳相位依赖关系，斜率为0.147°±0.018°−1，贡格带的平均绝对震级为6.100°±0.006°MAG。没有超过4%的旋转颜色变化。我们还观察到，日食发生在光线曲线最小值到0.3%的范围内，这要求两个天体中至少一个物体的长轴精确指向另一个天体。假设双星是双同步的，并且两个旋转轴都与轨道角动量矢量对齐，我们的观测联合约束了SILA和NUNAM的三轴形状模型，使得它们的长中轴比率的乘积为1.120±0.01.因此，两个主体都伸长6%，否则一个伸长6-12%，另一个伸长不到6%。
We combine long-term photometric observations in multiple band passes to determine the rotational light curve for the binary Kuiper-Belt object (79360) Sila–Nunam. We measure an unambiguous fundamental period of 6.2562 ± 0.002 d, within 0.02% of half the orbital period (Porb= 12.50995 ± 0.00036 d) determined earlier from HST observations resolving the binary. The light curve is double-peaked, and well fit by the sum of two sinusoids: a primary with periodPorb/2 and peak-to-peak amplitude 0.120 ± 0.012 mag and a secondary with periodPorband peak-to-peak amplitude 0.044 ± 0.010 mag. Excluding observations within ∼0.1 deg of opposition, we measure a linear solar phase dependence with slope 0.147 ± 0.018 mag deg−1and a mean absolute magnitude in the Gunngband of 6.100 ± 0.006 mag. There is no rotational color variation exceeding 4%. We also observe that eclipses occur centered on light curve minima to within 0.3%, requiring the long axis of at least one of the two bodies to point precisely toward the other. Assuming the binary is doubly synchronous and both rotation axes are aligned with the orbital angular momentum vector, our observations jointly constrain triaxial shape models for Sila and Nunam such that the product of their long-to-intermediate axes ratios is 1.120 ± 0.01. Hence both bodies are elongated by 6%, or else one is elongated by 6–12%, and the other by less than 6%.
影响因子：
3.2
作者：
F. Marchis;M. Kaasalainen;Erik F. Y. Hom;J. Berthier;J. Enriquez;D. Hestroffer;D. L. Mignant;I. Pater
通讯作者：
F. Marchis;M. Kaasalainen;Erik F. Y. Hom;J. Berthier;J. Enriquez;D. Hestroffer;D. L. Mignant;I. Pater