In a groundbreaking discovery, scientists have found a new exoplanet orbiting Barnard’s Star, the nearest single star to our Solar System, located just 5.96 light-years away. This small, rocky world, named Barnard b, has a mass of only 37% that of Earth, making it one of the smallest exoplanets ever detected. Although uninhabitable, the discovery marks a significant step toward finding Earth-sized planets scattered across the galaxy.
Barnard b is incredibly close to its host star, completing an orbit every 3.15 days at just 0.02 astronomical units (AU) from the red dwarf. Despite Barnard’s Star being much cooler than our Sun, this proximity makes the planet too hot to sustain liquid water or life as we know it. However, the discovery is still a scientific marvel, as detecting such small planets is notoriously difficult.
The exoplanet’s discovery follows earlier hints of a planetary signal near Barnard’s Star in 2018. Although that earlier signal indicated a larger planet, more recent observations using the European Southern Observatory’s Very Large Telescope have confirmed Barnard b’s presence through detailed measurements of the star’s radial velocity a slight wobble caused by the gravitational pull of the planet.
Astronomers also suspect that Barnard’s Star may host up to three more planets further out, but more observations are needed to confirm these findings. If proven, Barnard’s Star could become a hub of planetary exploration, providing valuable insights into planetary systems around red dwarf stars.
“This discovery opens a window into the presence of low-mass planets in our galactic neighborhood,” says Jonay González Hernández of the Institute of Astrophysics of the Canary Islands. “It highlights how much more there is to learn about planetary systems around red dwarfs.”
The discovery of Barnard b, alongside other nearby exoplanets like Proxima b, suggests that our cosmic backyard is teeming with small, rocky worlds. Further research could reveal whether these distant planets harbor conditions favorable for life. The study has been published in the journal Astronomy & Astrophysics.