A team of astronomers1 using ground-based telescopes in Hawaii, California and Arizona recently discovered a planetary system orbiting a nearby star that is only 54 light-years away. All three planets orbit their star at a distance closer than Mercury orbits the sun, completing their orbits in just 5, 15 and 24 days. Astronomers from the University of Hawaii at Mānoa, the University of California, Berkeley, the University of California Observatories2 and Tennessee State University found the planets using measurements from the Automated3 Planet Finder Telescope at Lick Observatory4 in California, the W. M. Keck Observatory on Maunakea, Hawaii and the Automatic Photometric Telescope at Fairborn Observatory in Arizona.The team discovered the new planets by detecting the wobble of the star HD 7924 as the planets orbited and pulled on the star gravitationally. APF and Keck Observatory traced out the planets orbits over many years using the Doppler technique that has successfully found hundreds of mostly larger planets orbiting nearby stars. APT made crucial measurements of the brightness of HD 7924 to assure the validity of the planet discoveries.
点击收听单词发音
1 astronomers n.天文学者，天文学家 参考例句： Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告将来日食月食的日期、时刻和时长。 来自《简明英汉词典》 Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为何只有土星有光环。 来自《简明英汉词典》
相关文章推荐
