GJ 1132 b
GJ 1132 b is a terrestrial planet orbiting GJ 1132 in the constellation Vela. It lies about 41 light-years from Earth and was discovered in 2015 using the transit method.
How Big Is GJ 1132 b?
GJ 1132 b has a radius of 1.19 times that of Earth. Its mass is 1.8 times that of Earth, giving it a density of 5.97 g/cm³ — comparable to rocky planets like Earth (5.51 g/cm³).
Is GJ 1132 b in the Habitable Zone?
GJ 1132 b orbits inside the inner edge of the habitable zone of GJ 1132. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of GJ 1132: 0.057–0.149 AU (conservative: 0.072–0.141 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on GJ 1132 b
The equilibrium temperature of GJ 1132 b is about 584 K (311 °C) — hotter than anywhere on Earth. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 19.30 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on GJ 1132 b — one full orbit around GJ 1132 — lasts just 39.1 hours, shorter than Mercury's 88-day year. It orbits at an average distance of 0.016 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.012).
How Was GJ 1132 b Discovered?
GJ 1132 b was discovered in 2015 using the transit method, with observations from Cerro Tololo Inter-American 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 GJ 1132 b?
GJ 1132 b is 41.1 light-years (12.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1985. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 723,360 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. GJ 1132 b scores 0.36, ranking #686 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: GJ 1132
GJ 1132
- Surface temperature
- 3,229 K (Sun: 5,772 K)
- Mass
- 0.19 M☉
- Radius
- 0.22 R☉
- Luminosity
- 0.0048 L☉
The GJ 1132 Planetary System
GJ 1132 b is one of 2 known planets in the GJ 1132 system. Its siblings:
- GJ 1132 c (Super Earth)
GJ 1132 b — Complete Data
| Radius | 1.192 Earth radii (0.106 Jupiter radii) |
|---|---|
| Mass | 1.84 Earth masses (0.006 Jupiter masses) |
| Density | 5.97 g/cm³ (Earth: 5.51) |
| Orbital period | 1.63 days |
| Orbital distance | 0.016 AU |
| Eccentricity | 0.012 |
| Equilibrium temperature | 584 K (311 °C) |
| Stellar irradiation | 19.30× Earth |
| Earth Similarity Index | 0.36 |
| Distance from Earth | 41.1 light-years (12.6 parsecs) |
| Constellation | Vela |
| Discovery method | Transit |
| Discovery facility | Cerro Tololo Inter-American Observatory |
| Discovery year | 2015 |
Data: NASA Exoplanet Archive, last updated 2024-09-03. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About GJ 1132 b
Is GJ 1132 b habitable?
No — GJ 1132 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is GJ 1132 b?
GJ 1132 b is about 41 light-years from Earth in the constellation Vela. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 723,360 years to get there.
How big is GJ 1132 b compared to Earth?
GJ 1132 b has 1.19 times the radius of Earth and about 1.8 times its mass.
How long is a year on GJ 1132 b?
One orbit around GJ 1132 takes 1.6 Earth days — short enough that 224 of its years would fit into one Earth year.
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