TESS uncovers Gaia23bra b via microlensing, a planet hidden in the data

NASA’s TESS has detected Gaia23bra b, a planet about 1.6 times Jupiter’s mass orbiting a distant orange-dwarf star roughly 40,000 light-years away, using gravitational microlensing—an effect predicted by Einstein’s general relativity. Hints of Gaia23bra b first appeared in Gaia data in 2023; microlensing provides a complementary route to exoplanet discovery alongside the transit method, and NASA’s Roman Space Telescope will use this technique to find about 1,000 microlensing planets in the Milky Way.