About this world
61 Vir b is a sub-Neptune orbiting 61 Vir, a yellow, Sun-like star (type G5V) 27.7 light-years from Earth. It is about 2.1 times the size of Earth (its size estimated from its mass), with at least 5.1 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 4.21 days at 0.05 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 1,178 K (905 °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 2009 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. 61 Vir has 3 known planets; the others are 61 Vir c and 61 Vir d.