环绕 Kepler-20 运行的两颗地球大小的行星
地球与行星天体物理
2011-12-21 v1
摘要
自发现环绕类太阳恒星的首批太阳系外巨行星以来，观测能力的不断演进使我们更接近于探测到真正的地球类似物。当一颗系外行星周期性地从其母星前方经过（凌星）时，会导致星光减弱，减弱程度与行星半径成正比，由此可测定系外行星的大小。迄今发现的最小系外行星半径为地球半径（R Earth）的 1.42 倍，体积为地球的 2.9 倍。在此我们报告在恒星 Kepler-20 周围发现两颗行星，一颗为地球大小（1.03R Earth），另一颗小于地球（0.87R Earth），已知该恒星还拥有另外三颗较大的凌星行星。新行星对母星的引力拉拽太小，无法用现有仪器测量。我们应用一种统计方法表明，将凌星信号解释为行星的似然度比解释为食双星信号的备择假设高出三个数量级以上。理论分析表明这些行星是岩质的，由铁和硅酸盐组成。外侧行星可能发育了厚的水蒸气大气层。
引用
@article{arxiv.1112.4550,
title = {Two Earth-sized planets orbiting Kepler-20},
author = {Francois Fressin and Guillermo Torres and Jason F. Rowe and David Charbonneau and Leslie A. Rogers and Sarah Ballard and Natalie M. Batalha and William J. Borucki and Stephen T. Bryson and Lars A. Buchhave and David R. Ciardi and Jean-Michel Desert and Courtney D. Dressing and Daniel C. Fabrycky and Eric B. Ford and Thomas N. Gautier and Christopher E. Henze and Matthew J. Holman and Andrew W. Howard and Steve B. Howell and Jon M. Jenkins and David G. Koch and David W. Latham and Jack J. Lissauer and Geoffrey W. Marcy and Samuel N. Quinn and Darin Ragozzine and Dimitar D. Sasselov and Sara Seager and Thomas Barclay and Fergal Mullally and Shawn E. Seader and Martin Still and Joseph D. Twicken and Susan E. Thompson and Kamal Uddin},
journal= {arXiv preprint arXiv:1112.4550},
year = {2011}
}
备注
Letter to Nature; Received 8 November; accepted 13 December 2011; Published online 20 December 2011