Star Measurements Hint at Many More Abodes for Life
See full article, by Ron Cowen, Science, Vol. 333 no. 6050 p. 1688, DOI: 10.1126/science.333.6050.1688
Reexamining a group of stars observed by NASA's Kepler spacecraft, astronomers say they have identified a trove of candidate planets that are both Earth-sized and potentially habitable. Scientists on the Kepler team had mistakenly pegged the candidates at about twice Earth's diameter and much too hot for life, the astronomers report in a paper posted 12 September on the arXiv preprint server (www.arXiv.org).
Philip Muirhead of the California Institute of Technology in Pasadena and his colleagues used infrared observations to make new, more accurate estimates of the sizes and masses of 84 stars less than half as massive as our sun, which Kepler had examined in visible light.
...The Caltech team's lower estimates of the sizes of stars place more of their candidate planets in the range where liquid water—and thus life—might exist.
...“This paper is a godsend,” says planet hunter Geoffrey Marcy of the University of California (UC), Berkeley. “My group is immediately going to adopt these new stellar radii and masses in our work to determine the occurrence of planets around stars of different types.”
The new findings for low-mass stars do not affect Kepler's search for planets around sunlike stars, Muirhead emphasizes. But because low-mass stars make up the majority of stars in the cosmos, he says, the results “strongly motivate us to redouble our efforts on these stars”—some of which lie only a few tens of light-years from Earth.
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