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HD 15082 (also known as WASP-33) is a star located roughly 378 light years away〔 in the northern constellation of Andromeda.〔(【引用サイトリンク】title=WASP-33 b )〕 The star is a Delta Scuti variable and a planetary transit variable. It is the first Delta Scuti variable known to host a planet.〔 A hot Jupiter type extrasolar planet orbits this star with an orbital period of 1.22 days. In common with many rapidly rotating stars of spectral type A, the stellar classification of HD 15082 is more challenging to discern. The hydrogen lines and effective temperature of the star are similar to spectral type A8, however the calcium II K line resembles that of an A5 star, and the metallic lines are more similar to an F4 star. The spectral type is thus written .〔 This suggests that HD 15082 is an Am star.〔 The exoplanet, HD 15082b (also known as WASP-33b) orbits so close to its star that its surface temperature is about . It is the hottest planet observed in the Universe. ==Planet== In 2010, the SuperWASP project announced the discovery of an extrasolar planet, designated HD 15082 b, orbiting the star. The discovery was made by detecting the transit of the planet as it passes in front of its star, an event which occurs every 1.22 days. As the planet crosses the star's disc, it causes the rotational broadening signature in the star's spectrum to change, enabling the determination of the sky-projected angle between the star's equator and the orbital plane of the planet to be determined. (This differs from the Rossiter–McLaughlin effect which is observed for radial velocity measurements). For HD 15082 b, this angle is about 250 degrees, indicating that it is in a retrograde orbit. Limits from radial velocity measurements imply it has less than 4.1 times the mass of Jupiter.〔 June 2015 NASA reported the exoplanet has a stratosphere, and the atmosphere contains titanium oxide which creates the stratosphere. Titanium oxide is one of only a few compounds that is a strong absorber of visible and ultraviolet radiation, which heats the atmosphere, and able to exist in a gas-state in a hot atmosphere. 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「HD 15082」の詳細全文を読む スポンサード リンク
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