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__NOTOC__ Kepler-7b is one of the first five exoplanets to be confirmed by NASA's Kepler spacecraft, and was confirmed in the first 33.5 days of Kepler's science operations.〔 It orbits a star slightly hotter and significantly larger than the Sun that is expected to soon reach the end of the main sequence.〔 Kepler-7b is a hot Jupiter that is about half the mass of Jupiter, but is nearly 1.5 times its size; at the time of its discovery, Kepler-7b was the second most diffuse planet known, surpassed only by WASP-17b.〔 It orbits its host star every five days at a distance of approximately . Kepler-7b was announced at a meeting of the American Astronomical Society on January 4, 2010. It is the first extrasolar planet to have a crude map of cloud coverage. ==Discovery== In 2009, NASA's Kepler spacecraft was completing the last of tests on its photometer, the instrument it uses to detect transit events, in which a planet crosses in front of and dims its host star for a brief and roughly regular period of time. In this last test, Kepler observed stars in the Kepler Input Catalog, including Kepler-7; the preliminary light curves were sent to the Kepler science team for analysis, who chose obvious planetary companions from the bunch for follow-up at observatories. Kepler-7 was not one of these original candidates.〔 After a resting period of 1.3 days, Kepler began a nonstop 33.5-day period in which it observed targets uninterrupted until June 15, 2009, when the collected data was downloaded and tested for false positives. Kepler-7's candidate was not found to be one of these false positives, such as an eclipsing binary star that may generate a light curve that mimics that of transiting planetary companions. Kepler-7 was then observed using Doppler spectroscopy using the Fibre-fed Echelle Spectrograph at the Canary Islands' Nordic Optical Telescope for ten nights in October 2009, taken with respect to the star HD 182488 to compensate for possible telescope error. Speckle imaging of the star was taken at WIYN Observatory in Arizona to check for close companions; when none were found, the High Resolution Echelle Spectrometer instrument at the W.M. Keck Observatory on Hawaii, the Harlan J. Smith Telescope at the McDonald Observatory in Texas, the PRISM camera at the Lowell Observatory, and the Faulkes Telescope North at the Haleakala Observatory on Maui were also used to analyze Doppler spectroscopy of the planetary candidate. The radial velocity observations confirmed that a planetary body was responsible for the dips observed in Kepler-7's light curve, thus confirming it as a planet.〔 Kepler's first discoveries, including the planets Kepler-4b, Kepler-5b, Kepler-6b, Kepler-7b, and Kepler-8b, were first announced on January 4, 2010, at the 215th meeting of the American Astronomical Society in Washington, D.C.〔 In May 2011, the planet was detected by brightness variations of the star cause by reflected starlight from the planet. It was found that Kepler-7b has a relatively high geometric albedo of 0.3. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Kepler-7b」の詳細全文を読む スポンサード リンク
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