About this world
Kepler-88 d is a gas giant orbiting KOI-142, a yellow, Sun-like star (type G) 1.23 thousand light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 3 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 3.84 years at 2.5 AU from its star, on a strongly elongated orbit (e = 0.41).
Its equilibrium temperature is about 159 K (−114 °C): too cold for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2020 by radial velocity with W. M. Keck Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. KOI-142 has 3 known planets; the others are KOI-142 b and KOI-142 c.