K2-70 b: A Neptune-Like World Orbiting a Cool Dwarf Star

K2-70 is a star located 760 light-years away, and it hosts one known planet. The star itself has a reported mass of 0.848 solar masses, a radius of 0.799 solar radii, and a temperature of 5130 K. Each of these estimates is smaller or cooler than the corresponding value for the Sun - the star is less massive, physically smaller, and cooler than our own.

The single planet in this system is K2-70 b, discovered in 2016 by the transit method, in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness. Repeated dips help establish the planet's orbital period, which is 14 days. K2-70 b is classified as Neptune-like, a size class that extends to four times Earth's radius, and its reported radius of 2.89 Earth radii is larger than Earth's. That radius places the planet in the Neptune-like size class, comparing its size - not its composition - with Earth's.