Exceptional astronomical seeing conditions above Dome C in Antarctica
Exceptional astronomical seeing conditions above Dome C in Antarctica
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DOI：
10.1038/nature02929
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发表时间：
2004-09-16
期刊：
影响因子：
64.8
通讯作者：
Travouillon, T
中科院分区：
文献类型：
--
作者：
Lawrence, JS;Ashley, MCB;Travouillon, T
在规划下一代地面光学天文望远镜时，最重要的考虑因素之一是选择一个具有良好“视宁度”的地点--当光线穿过地球大气层中折射率不同的区域时，光线弯曲会导致星星视位置的抖动。最好的中纬度观测点的视宁度中值在0.5到1.0弧秒之间（参考文献1-5）。南极高原上的地点具有独特的大气特性，值得作为潜在的观测地点进行调查。然而，在美国阿蒙森-斯科特南极站的先前测试显示，平均1.8弧秒的可见度很差（参考文献6，7）。在这里，我们报告了从南极高原上南纬75度的一个高点冰穹C（参考文献8）观测到的冬季景象。结果是显著的：平均视宁度为0.27弧秒，25%的时间低于0.15弧秒。放置在圆顶C的望远镜将与最好的中纬度天文台的2至3倍大的望远镜竞争，并且基于该站点的干涉仪可以用于否则需要空间使命的项目。
One of the most important considerations when planning the next generation of ground-based optical astronomical telescopes is to choose a site that has excellent 'seeing'-the jitter in the apparent position of a star that is caused by light bending as it passes through regions of differing refractive index in the Earth's atmosphere. The best mid-latitude sites have a median seeing ranging from 0.5 to 1.0 arcsec (refs 1-5). Sites on the Antarctic plateau have unique atmospheric properties that make them worth investigating as potential observatory locations. Previous testing at the US Amundsen-Scott South Pole Station has, however, demonstrated poor seeing, averaging 1.8 arcsec (refs 6, 7). Here we report observations of the wintertime seeing from Dome C (ref. 8), a high point on the Antarctic plateau at a latitude of 75 degrees S. The results are remarkable: the median seeing is 0.27 arcsec, and below 0.15 arcsec 25 per cent of the time. A telescope placed at Dome C would compete with one that is 2 to 3 times larger at the best mid-latitude observatories, and an interferometer based at this site could work on projects that would otherwise require a space mission.