About this world
K2-19 b is a Neptune-like planet orbiting K2-19, a yellow, Sun-like star (type G9) 945 light-years from Earth. It is about 0.62 times the size of Jupiter and holds 0.097 Jupiter masses. It completes an orbit every 7.92 days at 0.075 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 857 K (584 °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 2015 by transit with K2. A planet crosses its star and dims it by a tiny, periodic fraction. K2-19 has 3 known planets; the others are K2-19 d and K2-19 c.