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HD 107146
HD 107146 is a star in the constellation Coma Berenices that is located about 90 light years from Earth.〔 The apparent magnitude of 7.028 makes this star too faint to be seen with the unaided eye.
The physical properties of this star are similar to the Sun, including the stellar classification G2V,〔 making this a solar analog.〔 The mass of this star is about 109% of the solar mass () and it has about 99% the radius of the Sun ().〔 It is a young star with an age between 80 and 200 Myr.〔 The axis of rotation is estimated at degrees to the line of sight and it completes a rotation in a relatively brief 3.5 days.〔
==Circumstellar disc==
In 2003, astronomers recognized the excess infrared〔 and submillimeter〔 emission indicative of circumstellar dust, the first time such a debris disk phenomenon was noted around a star of similar spectral types to the Sun, though having a much younger age. In 2004 the Hubble Space Telescope detected the presence of a spatially resolved disk surrounding the star〔〔
The star's circumstellar disc has dimensions of approximately 210 x 300 AU.〔 The dusty ring is cool, with a temperature of 51 K, and has a mass of 0.10 Earth masses ().〔 Analysis of the debris disk in the far-infrared and submillimeter wavelengths, carried out using the Hubble Space Telescope, suggests the presence of small grains in the disk.〔 The disk appears to be slightly elongated to form an ellipse with its minor axis at a position angle of 58° ± 5°; working under the assumption that the disk is in fact circular gives it an inclination of 25° ± 5° from the plane of the sky.〔 An analysis published in 2009 suggests the possible presence of a planet at a separation of 45-75 AU.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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