About this world
GJ 273 b is a super-Earth orbiting GJ 273, a cool red dwarf (type M3.5) 19.3 light-years from Earth. It is about 1.5 times the size of Earth (its size estimated from its mass), with at least 2.9 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 18.6 days at 0.091 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 292 K (19 °C), which places it in the optimistic habitable zone: the band where liquid water could exist on a rocky surface. By the "cosmic shoreline", it has likely held on to an atmosphere.
It was discovered in 2017 by radial velocity with La Silla Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. GJ 273 has 2 known planets; the others are GJ 273 c.