Kepler-1398 is a star with 1.13 times the mass of the Sun, and 1.18 times its radius. It is located 2779.51 light years away from the solar system and is estimated to be 3.09 billion years old, as compared to the Sun which is roughly 4.6 billion years old.

Kepler-1398 is known to have 2 exoplanets in orbit around it.

Kepler-1398 b was discovered by the Kepler observatory, in 2016-05, using the transit method. Its semi-major axis is 0.04 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of Kepler-1398 b is 0.668 times the mass of Earth. The radius of Kepler-1398 b is 0.900 that of Earth. At less than 1.5 Earth masses, Kepler-1398 b is a regular terrestrial planet, much like the terrestrial planets we find in our solar system, namely Mercury, Venus, Earth and Mars.

Kepler-1398 c was discovered by the Kepler observatory, in 2016-05, using the transit method. Its semi-major axis is 0.05 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of Kepler-1398 c is 1.081 times the mass of Earth. The radius of Kepler-1398 c is 1.030 that of Earth. At less than 1.5 Earth masses, Kepler-1398 c is a regular terrestrial planet, much like the terrestrial planets we find in our solar system, namely Mercury, Venus, Earth and Mars.