LHS 1140 b
LHS 1140 b is an exoplanet orbiting within the conservative habitable zone of the red dwarf LHS 1140. Discovered in 2017 by the MEarth Project, LHS 1140 b is about 5.6 times the mass of Earth and about 70% larger in radius, putting it within the super-Earth category of planets. It was initially thought to be a dense rocky planet, but refined measurements of its mass and radius have found a lower density, indicating that it is likely an ocean world with 9-19% of its mass composed of water. LHS 1140 b orbits entirely within the star's habitable zone and gets 43% the incident flux of Earth. The planet is 49 light-years away and transits its star, making it an excellent candidate for atmospheric studies with ground-based and/or space telescopes.
Artist's impression of the planet LHS 1140 b and its host star | |
| Discovery | |
|---|---|
| Discovered by | MEarth Project |
| Discovery date | 20 April 2017 (Published) |
Detection method | Transit |
| Orbital characteristics | |
Semi-major axis | 0.0946±0.0017 AU |
| Eccentricity | <0.043 |
Orbital period (sidereal) | 24.7369148±0.0000058 d |
| Inclination | 89.86°±0.04° |
| Star | LHS 1140 |
| Physical characteristics | |
Mean radius | 1.730±0.025 R🜨 |
| Mass | 5.60±0.19 M🜨 |
Mean density | 5.9±0.3 g/cm3 |
| Temperature | 226±4 K (−47 °C; −53 °F, equilibrium) |