Free Astronomy Magazine May-June 2025

4 MAY-JUNE 2025 ASTRO PUBLISHING For a century, astronomers have been studying Barnard’s Star in the hope of finding planets around it. First discovered by E. E. Barnard at Yerkes Observatory in 1916, it is the nearest single star system to Earth. Barnard’s Star is classified as a red dwarf — low-mass stars that often host closely-packed planetary sys- tems, often with multiple rocky planets. Red dwarfs are extremely numerous in the Universe, so scien- tists are interested in understand- ing the environments of the planets they host. U sing in part the Gemini North telescope, one half of the In- ternational Gemini Observa- tory, partly funded by the U.S. Na- tional Science Foundation and oper- ated by NSF NOIRLab, astronomers have discovered four sub-Earth ex- oplanets orbiting Barnard’s Star, the nearest single star system to Earth. One of the planets is the least mas- sive exoplanet ever discovered us- ing the radial velocity technique, indicating a new benchmark for dis- covering smaller planets around nearby stars. by NOIRLab Josie Fenske & Louise Lerner Planetary system found around Barnard’s Star A rtist’s illustration of exoplanets orbiting Barnard’s Star. [Inter- national Gemini Observatory/NOIR- Lab/NSF/AURA/P. Marenfeld]