About this world
XO-2 S d is a gas giant orbiting XO-2 S, a yellow, Sun-like star (type G8V) 494 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 3.7 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 12.9 years at 5.5 AU from its star.
Its equilibrium temperature is about 111 K (−162 °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 2024 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. XO-2 S has 3 known planets; the others are XO-2 S b and XO-2 S c.