About this world
GJ 15 A b is a super-Earth orbiting GJ 15 A, a cool red dwarf (type M1) 11.6 light-years from Earth. It is about 1.6 times the size of Earth (its size estimated from its mass), with at least 3 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 11.4 days at 0.072 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 550 K (277 °C): far too hot for liquid water on its surface. By the "cosmic shoreline", it has likely held on to an atmosphere.
It was discovered in 2014 by radial velocity with W. M. Keck Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. GJ 15 A has 2 known planets; the others are GJ 15 A c.