最近的行星系距地球54光年

A team of astronomers¹ using ground-based telescopes in Hawaiʻi, 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 Hawaiʻi 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 (APF) Telescope at Lick Observatory⁴ in California, the W. M. Keck Observatory on Maunakea, Hawaiʻi and the Automatic Photometric Telescope (APT) 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.