Kepler-48: A Distant Star With Five Known Worlds

Kepler-48 is a star located 1000 light-years from Earth. It is 3.14 billion years old and has a reported mass of 0.88 solar masses, a radius of 0.89 solar radii, and a temperature of 5190 K, making it both smaller and cooler than the Sun. Five planets are known to orbit this star.

Kepler-48 b and Kepler-48 c were both found by the transit method in 2012. Kepler-48 b is a Super-Earth with a radius of 1.88 Earth radii and a mass of 3.94 Earth masses, circling its star every 4.78 days. Kepler-48 c is Neptune-like, with a radius of 2.71 Earth radii and a mass of 14.6 Earth masses, and an orbital period of 9.67 days. Both are larger and more massive than Earth.

Kepler-48 d, also classified as a Super-Earth, was discovered by transit in 2014. Its radius is 2.04 Earth radii and its mass is 7.93 Earth masses; it completes an orbit in 42.9 days. Like the other transiting planets here, it exceeds Earth in both radius and mass.

Two further planets were detected through the radial velocity method, which tracks the gravitational wobble a planet induces in its star. Kepler-48 e, announced in 2014, has a mass of 657 Earth masses and an orbital period of 982 days. Kepler-48 f, found in 2023, has a minimum mass of 299 Earth masses and takes 5220 days to orbit. Among the listed planets, Kepler-48 b has the shortest reported year, at 4.78 days, while Kepler-48 f has the longest, at 5220 days.