About this world
CI Tau c is a gas giant orbiting CI Tau, an orange dwarf (type K7) 515 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 3.6 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 25.2 days at 0.17 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.58).
Its equilibrium temperature is about 611 K (337 °C): far too hot 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.