About this world
HD 103197 b is a Neptune-like planet orbiting HD 103197, an orange dwarf (type K1V(P)) 186 light-years from Earth. It is about 5.8 times the size of Earth (its size estimated from its mass), with at least 29 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 47.8 days at 0.25 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 475 K (202 °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 2011 by radial velocity with La Silla Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum.