HIP 99770 b [1] is a directly imaged superjovian extrasolar planet orbiting the dusty A-type star HIP 99770 (29 Cygni), detected with Gaia/Hipparcos precision astrometry and high-contrast imaging.

The Subaru data utilized the observatory's extreme adaptive optics system, SCExAO, to correct for atmospheric turbulence and the CHARIS integral field spectrograph to detect HIP 99770 b at 22 different near-infrared wavelength passbands from 1.1 microns to 2.4 microns.

With a spectral type of L7.5--L9, HIP 99770 b lies at the L/T transition for substellar objects, transition from cloudy atmospheres without methane absorption to clear atmospheres with methane absorption.

The planet is likely intermediate in cloudiness between older, more massive field brown dwarfs and young L/T transition exoplanets like HR 8799 d. Jointly modeling relative astrometry of HIP 99770 b with absolute astrometry of the primary as measured by Gaia and Hipparcos yields precise estimates for the companion's orbit and mass.

HIP 99770 b is a super-jovian planet with a mass of roughly 16.1 times that of Jupiter.