Astronomers have confirmed the existence of four exoplanets orbiting Barnard’s Star, the second-closest star system to Earth after Alpha Centauri. The discovery, made using advanced spectrographic techniques, brings an end to decades of false claims and marks a major milestone in the search for life beyond our planet.
Barnard’s Star is a well-studied 10-billion-year-old M dwarf with a mass of 0.16 solar masses, located just six light-years from Earth. The discovery was made using data from the MAROON-X spectrograph and ESPRESSO, which were used to observe Barnard’s Star from 2021 to 2023.
The team found three confirmed planets, Barnard b, c, and d, with periods of 2.34, 3.15, and 4.12 days, respectively. However, further analysis revealed a fourth planet, e, with a period of 6.74 days. The newly discovered planet has the lowest mass detected using this method.
The planets are in remarkably close quarters, which raises questions about their long-term stability. Using machine learning algorithms, the team found that if the orbits were perfectly circular, the system would be stable long term. However, with more realistic orbital parameters, the system became unstable within just 2,000 years.
Despite being outside the habitable zone of Barnard’s Star, which spans from 10 to 42 days, the team suggests that smaller planets could still exist in this region. Further research is needed to determine the orbits and stability of these new exoplanets and their potential for supporting life.
Source: https://skyandtelescope.org/astronomy-news/confirmed-at-last-barnards-star-hosts-four-tiny-planets