- Barnard's Star is the closest single star system to Earth, located less than 6 light-years away, and hosts four confirmed exoplanets discovered between 2024 and 2025.
- These exoplanets have masses between Earth and Mars but are likely uninhabitable due to high levels of periclase (magnesium oxide) that prevent water storage.
- The planets orbit extremely close to their star (1% to 4% of Earth-Sun distance), are tidally locked, and lost their atmospheres after about 2 billion years due to stellar radiation.
- Despite instability risks, the three inner planets maintain orbital resonance (9:12:16) which stabilizes the system.
- The research, published in Monthly Notices of the Royal Astronomical Society, links stellar and planetary composition to assess habitability, aiding future missions like PLATO.