About this world
tau Cet g is an Earth-sized planet orbiting tau Cet, a yellow, Sun-like star (type G8.5V) 11.8 light-years from Earth. It is about 1.2 times the size of Earth (its size estimated from its mass), with at least 1.8 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 20 days at 0.13 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 640 K (367 °C): far too hot for liquid water on its surface. By the "cosmic shoreline", its star has probably stripped its atmosphere away, leaving bare rock.
It was discovered in 2017 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. tau Cet has 3 known planets; the others are tau Cet h and tau Cet f.