50光年到飞马座51号
(原标题: 50 Light-years to 51 Pegasi)
2021-10-09
浏览次数: 34
距离飞马座51号只有50光年。这张8月份拍摄的照片显示了这颗恒星的位置，这是在一个朦胧的夜晚拍摄的，在法国上普罗旺斯天文台的圆顶上方，可以看到大多数较亮的恒星。26年前，也就是1995年10月，天文学家米歇尔·马约尔和迪迪埃·奎洛兹宣布了在天文台的一项重大发现。通过精密的光谱仪，他们发现了一颗围绕51peg运行的行星，这是已知的第一颗围绕类太阳恒星运行的系外行星。马约尔和奎洛兹用摄谱仪测量了恒星径向速度的变化，这是一种由绕轨道运行的行星的引力牵引引起的有规律的摆动。这颗行星被命名为51 Pegasi b，其质量至少是木星质量的一半，轨道周期为4.2天，这使得它与母恒星的距离比水星与太阳的距离要近得多。他们的发现很快得到了证实，Mayor和Queloz最终在2019年获得了诺贝尔物理学奖。现在被认为是被亲切地称为热木星的系外行星的原型，51pegasi b在2015年被正式命名为Dimidium，拉丁语的意思是“一半”。自发现以来，已经发现了4000多颗系外行星。
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It's only 50 light-years to 51 Pegasi. That star's position is indicated in this snapshot from August, taken on a hazy night with mostly brighter stars visible above the dome at Observatoire de Haute-Provence in France. Twenty-six years ago, in October of 1995, astronomers Michel Mayor and Didier Queloz announced a profound discovery made at the observatory. Using a precise spectrograph they had detected a planet orbiting 51 Peg, the first known exoplanet orbiting a sun-like star. Mayor and Queloz had used the spectrograph to measure changes in the star's radial velocity, a regular wobble caused by the gravitational tug of the orbiting planet. Designated 51 Pegasi b, the planet was determined to have a mass at least half of Jupiter's mass and an orbital period of 4.2 days, making it much closer to its parent star than Mercury is to the Sun. Their discovery was quickly confirmed and Mayor and Queloz were ultimately awarded the Nobel Prize in physics in 2019. Now recognized as the prototype for the class of exoplanets fondly known as hot Jupiters, 51 Pegasi b was formally named Dimidium, latin for half, in 2015. Since its discovery, over 4,000 exoplanets have been found.
© Josselin Desmars