A research team has discovered a new exoplanet, named Barnard b, located just six light-years from Earth, orbiting the red dwarf star Barnard's Star in the constellation Ophiuchus. This finding marks a significant addition to the known exoplanets in our cosmic neighborhood.
Barnard's Star is the closest known star system to Earth after Alpha Centauri, which includes Proxima Centauri. The study, published in the journal Astronomy & Astrophysics, was led by Jonay González Hernández from the Instituto de Astrofísica de Canarias.
The team initially searched for exoplanets within the habitable zone of Barnard's Star, where liquid water could exist. However, Barnard b orbits its star at a distance twenty times closer than Mercury does to the Sun, completing an orbit in just 3.15 Earth days. This proximity results in surface temperatures around 125 degrees Celsius, making it inhospitable for liquid water.
To detect Barnard b, the team utilized the high-precision instrument ESPRESSO from the European Southern Observatory, which measures the star's wobble caused by gravitational interactions with orbiting planets. Barnard b is noted as one of the least massive known exoplanets, weighing approximately half that of Venus.
While a potential exoplanet around Barnard's Star was reported in 2018, it has not been confirmed. The new data does not support the existence of that body but has revealed three additional exoplanet candidates around the star, which remain unconfirmed. Future observations will be necessary to verify these candidates, according to co-author Alejandro Suárez Mascareño.
This discovery reinforces the notion that our local cosmic neighborhood is rich with low-mass planets, similar to Proxima b and d.