Kepler-1740 and Its Lone Known Planet

Kepler-1740 is a star 3460 light-years away with one known planet in orbit around it. The star is slightly more massive than the Sun, at 1.02 solar masses, though its radius is somewhat smaller, at 0.931 solar radii. Its temperature is 5710 K. A solar mass compares a star's mass with the Sun's, while a solar radius compares its radius with the Sun's.

The single known planet is Kepler-1740 b, a Neptune-like world discovered in 2021 by the transit method. During a transit, a planet passes in front of its star from our viewpoint and causes a small dip in the star's observed brightness; repeated dips help establish orbital periods. Kepler-1740 b completes an orbit every 8.17 days and has a radius of 3.32 Earth radii. That makes it larger than Earth. Planet size classes compare radius with Earth's, and a Neptune-like planet reaches 4 times Earth's radius.