The quest for Earth-like planets represents a major focus of current exoplanet research. While planets that are Earth-sized and smaller have been detected, these planets reside in orbits that are too close to their host star to allow liquid water on their surface. We present the detection of Kepler-186f, a 1.11+\-0.14 Earth radius planet that is the outermost of five planets - all roughly Earth-sized - that transit a 0.47+\-0.05 Rsun star. The intensity and spectrum of the star's radiation places Kepler-186f in the stellar habitable zone, implying that if Kepler-186f has an Earth-like atmosphere and H2O at its surface, then some of this H2O is likely to be in liquid form.
@article{arxiv.1404.5667,
title = {An Earth-sized Planet in the Habitable Zone of a Cool Star},
author = {Elisa V. Quintana and Thomas Barclay and Sean N. Raymond and Jason F. Rowe and Emeline Bolmont and Douglas A. Caldwell and Steve B. Howell and Stephen R. Kane and Daniel Huber and Justin R. Crepp and Jack J. Lissauer and David R. Ciardi and Jeffrey L. Coughlin and Mark E. Everett and Christopher E. Henze and Elliott Horch and Howard Isaacson and Eric B. Ford and Fred C. Adams and Martin Still and Roger C. Hunter and Billy Quarles and Franck Selsis},
journal= {arXiv preprint arXiv:1404.5667},
year = {2014}
}
Comments
Main text and supplemental material combined. This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science on 18 April 2014, Vol. 344, #6181. Published version available from http://www.sciencemag.org/content/344/6181/277