Large-amplitude photometric variations of Nereid
Large-amplitude photometric variations of Nereid
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DOI：
10.1038/333436a0
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发表时间：
1988-03
期刊：
影响因子：
64.8
通讯作者：
M. Schaefer;B. Schaefer
中科院分区：
文献类型：
--
作者：
M. Schaefer;B. Schaefer
海卫二是海王星的两颗已知卫星之一，于1949年由柯伊伯1发现。它有一个非常偏心的轨道（e = 0.75），因此它与海王星的距离从140万到970万公里不等，周期为1360天。除了由柯伊伯1确定的照相星等（mp = 19.5）的粗略估计外，没有关于海卫二的光度数据。1987年6月，我们在Cerro Tololo美洲天文台（CTIO）使用0.9米望远镜和CCD相机收集了有关Nereid的测光（UBVRI）和天体测量数据。我们得到了四个天体测量位置和UBVRI反射率跨越8天。根据这些数据，确定了沙蚕的一个不寻常的反射光谱。在所有的带通中都观察到海卫二的变化，振幅大于1.5等，周期可能在8到24小时之间。
Nereid, one of the two known satellites of Neptune, was discovered in 1949 by Kuiper1. It has an extremely eccentric orbit (e ≃ 0.75), such that its distance from Neptune varies from ∼1.4 to 9.7 million km, with a period of ∼360 days. No photometric data exist for Nereid2other than the rough estimate of photographic magnitude (mp = 19.5) determined by Kuiper1. In June 1987 we collected photometric (UBVRI) and astrometric data on Nereid using the 0.9-m telescope and CCD camera at the Cerro Tololo Inter-American Observatory (CTIO). We obtained four astrometric positions and UBVRI reflectances spanning 8 days. From these data, an unusual reflectance spectrum for Nereid was determined. Variability of Nereid was observed in all bandpasses, with an amplitude of greater than 1.5 mag, and a probable period of between 8 and 24 h.