由加州理工学院科学家领导的小组利用开普勒望远镜的数据发现了18颗新的系外行星.doc

由加州理工学院科学家领导的小组利用开普勒望远镜的数据发现了18颗新的系外行星。这些行星都是围绕大质量A型恒星的长周期类木行星。大恒星有更多的大行星，这符合行星吸积理论的预言。意味着占银河系大多数的小质量恒星应该拥有大量的类地行星。 The twin telescopes at Keck Observatory in Hawaii. The astronomers used Keck to discover 18 new Jupiter-like planets orbiting massive stars. Credit: Rick Peterson/ W.M. Keck Observatory Discoveries of new planets just keep coming and coming. Take, for instance, the 18 recently found by a team of astronomers led by scientists at the California Institute of Technology (Caltech). 2 Download mp3 ?iTunes podcast ?Latest podcasts ?About Share to facebook PHYS on FB Tweet PHYS on Twitter inShare1 Reddit Google Delicious Slashdot Yahoo! bookmarks Windows Live RSS QR code Ads by Google Solar Energy Stocks - Three solar stocks youve never heard of, looking past the obvious - EnergyandC/Solar_Company Its the largest single announcement of planets aside from the discoveries made by the Kepler mission, says John Johnson, assistant professor of astronomy at Caltech and the first author on the teams paper, which was published in the December issue of The Astrophysical Journal Supplement Series. The Kepler mission is a space telescope that has so far identified more than 1,200 possible planets, though the majority of those have not yet been confirmed. Using the Keck Observatory in Hawaii—with follow-up observations using the McDonald and Fairborn Observatories in Texas and Arizona, respectively—the researchers surveyed about 300 stars. They focused on those dubbed retired A-type stars that are more than one and a half times more massive than the sun. These stars are just past the main stage of their life—hence, retired—and are now puffing up into whats called a subgiant star. To look for planets, the astronomers searched for stars of this type that wobble, which could be caused by the gravitational tug of an orbiting planet. By searching the wobbly stars spectra for Doppler shifts—the lengthening and contracting of wavelengths due to