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WASP-44 is a G-type star in constellation Cetus that has the Jupiter-size planet WASP-44b in orbit. The star is slightly less massive and slightly smaller than the Sun; it is also slightly cooler, but is more metal-rich. The star was observed by SuperWASP, an organization in search of planets, starting in 2009; manual follow-up observations used WASP-44's spectrum and measurements of its radial velocity led to the discovery of the transiting planet WASP-44b. The planet and its star were presented along with WASP-45b and WASP-46b on May 17, 2011 by a team of scientists testing the idea that Hot Jupiters tend to have circular orbits, an assumption that is made when the orbital eccentricity of such planets are not well-constrained.〔 ==Observational history== WASP-44 was observed between July and November 2009 by the WASP-South, a station of the SuperWASP planet-searching program based at the South African Astronomical Observatory. Observations of the star revealed a periodic decrease in its brightness. WASP-South, along with the SuperWASP-North station at the Roque de los Muchachos Observatory on the Canary Islands, collected 15,755 photometric observations, allowing scientists to produce a more accurate light curve.〔 Another set of observations yielded a 6,000 point photometric data set, but the light curve was prepared late and was not considered in the discovery paper.〔 In 2010, a European science team investigated the star using the CORALIE spectrograph and collected seventeen spectra of WASP-44. From the spectra, radial velocity measurements were extrapolated. Analysis of collected CORALIE data ruled out the possibility that the detected radial velocity was caused by the blended spectrum of a spectroscopic binary star, supporting the possibility that the body orbiting WASP-44 was indeed a planet, designated WASP-44b.〔 The Leonhard Euler Telescope at La Silla Observatory in Chile was used to follow up on the discovery circling WASP-44, searching for a point at which the planet transited, or crossed in front of, its host star. One transit was detected.〔 WASP-44, its recently discovered planet, the planets orbiting WASP-45 and WASP-46, and a discussion exploring the validity of the common assumption amongst scientists that closely orbiting Hot Jupiter planets have highly circular orbits unless proven otherwise, were reported in a single discovery paper that was published on May 17, 2011 by the Royal Astronomical Society.〔 The paper was submitted to the ''Monthly Notices of the Royal Astronomical Society'' on May 16, 2011.〔 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「WASP-44」の詳細全文を読む スポンサード リンク
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