Nature2014-06-24 3:10 PM

矮行星Sedna不是孤立的 A Sedna-like body with a perihelion of 80 astronomical units

论文摘要 

太阳系形成模型预测,遥远的、直径为1000公里的矮行星Sedna (在其最近点、即近日点距太阳76个天文单位),可能是在30-50个天文单位的距离处绕轨道运行的柯伊伯带天体与尚未看到的“外Oort云”(距太阳10,000个天文单位)之间的一个联系。现在,Chadwick Trujillo 和 Scott Sheppard报告了第二个与Sedna相似天体的存在,即2012 VP113,近日点为80个天文单位。这一发现证实,Sedna不是一个孤立的天体。这两个天体可能是一组“内Oort云”天体的成员,它们的数量可能超过太阳系中所有其他动态稳定的天体类群。

Abstract 

The observable Solar System can be divided into three distinct regions: the rocky terrestrial planets including the asteroids at 0.39 to 4.2 astronomical units (AU) from the Sun (where 1 AU is the mean distance between Earth and the Sun), the gas giant planets at 5 to 30 AU from the Sun, and the icy Kuiper belt objects at 30 to 50 AU from the Sun. The 1,000-kilometre-diameter dwarf planet Sedna was discovered ten years ago and was unique in that its closest approach to the Sun (perihelion) is 76 AU, far greater than that of any other Solar System body. Formation models indicate that Sedna could be a link between the Kuiper belt objects and the hypothesized outer Oort cloud at around 10,000 AU from the Sun. Here we report the presence of a second Sedna-like object, 2012 VP113, whose perihelion is 80 AU. The detection of 2012 VP113 confirms that Sedna is not an isolated object; instead, both bodies may be members of the inner Oort cloud, whose objects could outnumber all other dynamically stable populations in the Solar System.

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