GJ 1132 b
GJ 1132 b (also known as Gliese 1132 b) is an exoplanet orbiting the red dwarf star GJ 1132 41 light-years (13 parsecs) from Earth, in the constellation Vela. The planet is considered uninhabitable but cool enough to possess an atmosphere. GJ 1132 b was discovered by the MEarth-South array in Chile.
Size comparison of GJ 1132 b with Earth. | |
| Discovery | |
|---|---|
| Discovered by | MEarth-South Array Team |
| Discovery site | Chile |
| Discovery date | May 10, 2015 (announced) November 12, 2015 (confirmed) |
Detection method | Transit |
| Orbital characteristics | |
Semi-major axis | 0.0153±0.0005 AU |
| Eccentricity | <0.22 |
Orbital period (sidereal) | 1.6289304(13) d |
| Inclination | 86.58°±0.63° |
| Semi-amplitude | 2.85±0.34 m/s |
| Star | GJ 1132 |
| Physical characteristics | |
Mean radius | 1.130±0.056 R🜨 |
| Mass | 1.66±0.23 M🜨 |
Mean density | 6.3±1.3 g/cm3 |
Surface gravity | 12.9±2.2 m/s2 |
| 13.6±1.0 km/s | |
It has been called "one of the most important planets ever discovered beyond the Solar System": Due to its relative proximity to Earth, telescopes should be able to determine the composition of its atmosphere, the speed of its winds and the color of its sunsets. This is due in part to the small diameter of its parent star (20% that of the Sun), which increases the effect on the star's light of its transits. The planet's diameter is approximately 20% larger than that of the Earth and its mass is estimated at 1.6 times that of Earth, implying that it has an Earth-like rocky composition. GJ 1132 b orbits its star every 1.6 days at a distance of 1.4 million miles (2.24 million kilometres).
The planet receives 19 times more stellar radiation than Earth. The equilibrium temperature is estimated at 529 K (256 °C; 493 °F) for an Earth-like albedo, or 409 K (136 °C; 277 °F) for a Venus-like albedo. The planet is likely to be hotter than Venus, as higher temperatures likely prevail at the surface if the planet has an atmosphere. It is possible that the night side of the planet is cooler, because it is presumed to be tidally locked due to its proximity to its star; however, under most circumstances where an atmosphere is thick, it would be able to transfer heat to the far side.