On October 1, 2024, astronomers announced the discovery of a new exoplanet, named Barnard b, orbiting Barnard's Star, the closest star to our solar system, located just six light-years away. This rocky planet has a mass at least half that of Venus and completes an orbit in approximately three Earth days.
Despite its proximity, Barnard b is not in the habitable zone, as its surface temperature reaches around 125°C, making it inhospitable for liquid water, a key ingredient for life. The findings were published in the journal Astronomy and Astrophysics following five years of observations using the Very Large Telescope (VLT) in Chile.
Jonay González Hernández, a researcher from the Instituto de Astrofísica de Canarias and the lead author of the study, emphasized that Barnard b is one of the smallest known exoplanets, with a mass less than that of Earth. Although Barnard's Star is about 2,500°C cooler than the Sun, the extreme proximity of Barnard b results in excessive heat on its surface.
Additionally, the research team detected signals suggesting the possible existence of three more exoplanets orbiting Barnard's Star, but further observations are needed to confirm these findings. The discovery highlights the potential richness of our cosmic neighborhood, particularly in low-mass planets.
The study of Barnard b and its companions could enhance our understanding of planetary systems around red dwarf stars, which are known to host rocky planets more easily detectable than those around larger stars.