Gliese 832 b (Gl 832 b or GJ 832 b) is a gas giant exoplanet about 80% the mass of Jupiter, located 16.2 light-years from the Sun in the constellation of Grus, orbiting the red dwarf star Gliese 832.

Orbit

The planet takes 9.88 years to revolve around its star at an orbital distance of 3.5 AU; at the time of discovery, this was the longest-period Jupiter-like planet known orbiting a red dwarf. The brightness of the faint parent star at that distance corresponds to the brightness of the Sun from 80 AU (or 100 times brighter than a full Moon as seen from Earth).

Discovery

The planet was discovered at the Anglo-Australian Observatory on September 1, 2008. It would induce an astrometric perturbation on its star of at least 0.95 milliarcseconds and is thus a good candidate for being detected by astrometric observations. Despite its relatively large angular distance, direct imaging is problematic due to the star–planet contrast. Gliese 832 b was confirmed and its parameters updated by subsequent studies in 2011, 2014, and 2022. In 2023, an astrometric detection of the planet was announced, determining its inclination and revealing a true mass 80% the mass of Jupiter.