LP 890-9 c
LP 890-9 c is a super-Earth orbiting the M6 V star LP 890-9 in the constellation Eridanus. It lies about 106 light-years from Earth and was discovered in 2022 using the transit method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.
How Big Is LP 890-9 c?
LP 890-9 c has a radius of 1.37 times that of Earth. Its mass is 25.3 times that of Earth.
Is LP 890-9 c in the Habitable Zone?
LP 890-9 c orbits inside the conservative habitable zone of LP 890-9 — the region where a rocky planet could sustain liquid water on its surface. This makes it one of the most interesting known exoplanets in the search for life.
Habitable zone of LP 890-9: 0.031–0.084 AU (conservative: 0.040–0.079 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Temperature on LP 890-9 c
The equilibrium temperature of LP 890-9 c is about 272 K (-1 °C) — in a range broadly comparable to Earth, whose equilibrium temperature is 255 K. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 0.91 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on LP 890-9 c — one full orbit around LP 890-9 — lasts 8.46 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.040 AU — closer to its star than Mercury is to the Sun.
How Was LP 890-9 c Discovered?
LP 890-9 c was discovered in 2022 using the transit method, with observations from SPECULOOS Southern Observatory.
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is LP 890-9 c?
LP 890-9 c is 105.8 light-years (32.4 parsecs) from Earth. Light arriving here tonight left the planet around the year 1921. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,862,080 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. LP 890-9 c scores 0.89, ranking #6 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: LP 890-9
LP 890-9
- Spectral type
- M6 V
- Surface temperature
- 2,850 K (Sun: 5,772 K)
- Mass
- 0.12 M☉
- Radius
- 0.16 R☉
- Luminosity
- 0.0014 L☉
- Age
- 7.2 billion years (Sun: 4.6)
The LP 890-9 Planetary System
LP 890-9 c is one of 2 known planets in the LP 890-9 system. Its siblings:
- LP 890-9 b (Super Earth)
LP 890-9 c — Complete Data
| Radius | 1.367 Earth radii (0.122 Jupiter radii) |
|---|---|
| Mass | 25.30 Earth masses (0.080 Jupiter masses) |
| Orbital period | 8.46 days |
| Orbital distance | 0.040 AU |
| Equilibrium temperature | 272 K (-1 °C) |
| Stellar irradiation | 0.91× Earth |
| Earth Similarity Index | 0.89 |
| Distance from Earth | 105.8 light-years (32.4 parsecs) |
| Constellation | Eridanus |
| Discovery method | Transit |
| Discovery facility | SPECULOOS Southern Observatory |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2022-09-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About LP 890-9 c
Is LP 890-9 c habitable?
LP 890-9 c orbits within the habitable zone of LP 890-9, the region where liquid water could exist on a planet's surface. It sits in the conservative habitable zone — the most promising region for habitability. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.
How far away is LP 890-9 c?
LP 890-9 c is about 106 light-years from Earth in the constellation Eridanus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,862,080 years to get there.
How big is LP 890-9 c compared to Earth?
LP 890-9 c has 1.37 times the radius of Earth and about 25.3 times its mass.
How long is a year on LP 890-9 c?
One orbit around LP 890-9 takes 8.5 Earth days — short enough that 43 of its years would fit into one Earth year.