LHS 1140 is a star with 0.18 times the mass of the Sun, and 0.21 times its radius. It is located 48.88 light years away from the solar system and is estimated to be 5 billion years old, as compared to the Sun which is roughly 4.6 billion years old.
LHS 1140 is known to have 2 exoplanets in orbit around it.
LHS 1140 b was discovered by the MEarth Project observatory, in 2017-04, using the transit method. Its semi-major axis is 0.09 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of LHS 1140 b is 6.983 times the mass of Earth. The radius of LHS 1140 b is 1.727 that of Earth. At more than 10 Earth masses, LHS 1140 b is an ice giant, a planet that is made up mostly of volatiles like water, amonia and methane, and enveloped by a dense hydrogen and helium atmosphere, much like Uranus and Neptune in our solar system.
LHS 1140 c was discovered by the Multiple Observatories observatory, in 2019-01, using the transit method. Its semi-major axis is 0.03 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of LHS 1140 c is 1.809 times the mass of Earth. The radius of LHS 1140 c is 1.282 that of Earth. At 1.809 Earth masses, LHS 1140 c is a so called Super Earth. Super Earths could be terrestrial worlds like Earth, but they could also be ocean worlds or terrestrial worlds wrapped in a substantial atmosphere, in which case some refer to them as Mini Neptunes. No Super Earths are known to exist in our solar system, but if it exists, the so-called Planet Nine could very well be a super Earth, as it is hypothesized to have a mass between five and ten Earth masses.