HD 155233 b

HD 155233 b is a confirmed brown dwarf orbiting around the K-type giant star HD 155233 every 826 days, some 244 light-years away. It has a minimum mass of almost 3 times that of Jupiter, and so was initially thought to be a gas giant exoplanet similar to Jupiter. However, in 2023 the inclination and true mass of HD 155233 b were determined via astrometry, showing it to be a brown dwarf about 32 times the mass of Jupiter in a nearly face-on orbit.

HD 155233 b was discovered by Wittenmyer et al. in October 2015. The orbit and mass were refined in 2016, and again in 2023.