LSPM J2116+0234 b
LSPM J2116+0234 b is a Neptune-like planet orbiting the M3.0 V star LSPM J2116+0234 in the constellation Equuleus. It lies about 58 light-years from Earth and was discovered in 2019 using the radial velocity method.
Is LSPM J2116+0234 b in the Habitable Zone?
LSPM J2116+0234 b orbits inside the inner edge of the habitable zone of LSPM J2116+0234. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of LSPM J2116+0234: 0.116–0.301 AU (conservative: 0.147–0.285 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Orbit and Year Length
A year on LSPM J2116+0234 b — one full orbit around LSPM J2116+0234 — lasts 14.4 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.088 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.18).
How Was LSPM J2116+0234 b Discovered?
LSPM J2116+0234 b was discovered in 2019 using the radial velocity method, with observations from Calar Alto Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is LSPM J2116+0234 b?
LSPM J2116+0234 b is 57.5 light-years (17.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1969. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,012,000 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. LSPM J2116+0234 b scores 0.48, ranking #274 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: LSPM J2116+0234
LSPM J2116+0234
- Spectral type
- M3.0 V
- Surface temperature
- 3,475 K (Sun: 5,772 K)
- Mass
- 0.43 M☉
- Radius
- 0.43 R☉
- Luminosity
- 0.0200 L☉
- Age
- 2.0 billion years (Sun: 4.6)
Planetary System
LSPM J2116+0234 b is the only planet known to orbit LSPM J2116+0234 so far.
LSPM J2116+0234 b — Complete Data
| Mass (best estimate) | 13.30 Earth masses |
|---|---|
| Orbital period | 14.44 days |
| Orbital distance | 0.088 AU |
| Eccentricity | 0.183 |
| Earth Similarity Index | 0.48 |
| Distance from Earth | 57.5 light-years (17.6 parsecs) |
| Constellation | Equuleus |
| Discovery method | Radial Velocity |
| Discovery facility | Calar Alto Observatory |
| Discovery year | 2019 |
Data: NASA Exoplanet Archive, last updated 2019-06-07. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About LSPM J2116+0234 b
Is LSPM J2116+0234 b habitable?
No — LSPM J2116+0234 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is LSPM J2116+0234 b?
LSPM J2116+0234 b is about 58 light-years from Earth in the constellation Equuleus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,012,000 years to get there.
How long is a year on LSPM J2116+0234 b?
One orbit around LSPM J2116+0234 takes 14.4 Earth days — short enough that 25 of its years would fit into one Earth year.
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