K2-340 b: A Neptune-Like World Orbiting a Distant Star

K2-340 is a star located 2410 light-years away. It has a reported mass estimate of 0.93 solar masses, a radius estimate of 1.13 solar radii, and a temperature of 5530 K. Its reported mass estimate is smaller than the Sun's, while its reported radius estimate is larger than the Sun's. The star's reported temperature is cooler than the Sun's. One planet is known to orbit this host.

K2-340 b is a Neptune-like planet discovered by the transit method in 2021. This discovery method detects the small dip in observed brightness caused when a planet passes in front of its star from our viewpoint; repeated dips help establish orbital periods. The planet completes an orbit every 29.7 days. Its radius estimate is 3.36 Earth radii, which is larger than Earth's. As a Neptune-like planet, its size classification places it within four times Earth's radius.