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=11.79 and the absolute magnitude of the Sun 〕 | temperature = 〔 }} Gliese 876 is a red dwarf approximately 15 light-years away from Earth in the constellation of Aquarius. It is the third closest known star to the Sun confirmed to possess a planetary system (after Gliese 674 and Epsilon Eridani) and the closest such system known to consist of multiple planets. As of 2011, four extrasolar planets have been found to orbit the star. The planetary system is also notable for the orbital properties of its planets. It is the only known system of orbital companions to exhibit a triple conjunction in the rare phenomenon of Laplace resonance (a type of resonance first noted in Jupiter's inner three Galilean moons). It is also the first extrasolar system around a normal star with measured coplanarity. Two of the middle planets are located in the system's habitable zone, however they are giant planets believed to be analogous to Jupiter. == Distance and visibility == Gliese 876 is located fairly close to the Solar System. According to astrometric measurements made by the Hipparcos satellite, the star shows a parallax of 213.28 milliarcseconds,〔 which corresponds to a distance of , currently making it the third closest known star with orbiting planets, after Epsilon Eridani and Gliese 674.〔 Despite being located so close to Earth, the star is so faint that it is invisible to the naked eye and can only be seen using a telescope. 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「Gliese 876」の詳細全文を読む スポンサード リンク
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