Illustration of Barnard's star (right) and an exoplanet. Barnard's star is a red dwarf between 7??2 billion years old located about 6 light-years from Earth in the constellation of Ophiuchus. The brightness of Barnard's star varies due to high energy flares. It has an orbiting exoplanet, Barnard star b (also known as GJ 699 b). The exoplanet was discovered in 2018 and is thought to be around three times the mass of Earth, orbiting the star every 233 days. The temperature of the exoplanet has been calculated to be around 103 Kelvin, too cold for liquid water to exist.