Exoplanet · Earth-sized rocky planet
TRAPPIST-1 b
TRAPPIST-1 b is a Earth-sized rocky planet orbiting the star TRAPPIST-1. Its year lasts 1.51 Earth days. It was discovered in 2016 by the Transit method.
| Host star | TRAPPIST-1 |
|---|---|
| Distance | 40.5 light-years (12.4 pc) |
| Orbital period | 36.3 hours |
| Orbital radius | 0.0115 AU |
| Eccentricity | 0.006 |
| Radius | 1.12 R⊕ · 0.0996 R♃ |
| Mass | 1.37 M⊕ · 0.00432 M♃ |
| Density | 5.44 g/cm³ |
| Surface gravity | 1.1 × Earth |
| Equilibrium temperature | 398 K (124 °C) |
| Stellar flux received | 4.15 × Earth |
| Discovery method | Transit |
| Discovery year | 2016 |
| Discovered by | La Silla Observatory |
Habitable zone
Inside the inner edge of the habitable zone: it receives 4.15 times the light the Earth does, too hot to keep liquid water on its surface.
Its star in the sky
In the planet's sky its star is a disc 5.5° across: 10 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 18.65. Visible from the whole Southern Hemisphere and north to latitude 85° N. It stands highest at midnight in September, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1985. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 719 thousand years.
Planets in the same system
- TRAPPIST-1 c 2.42-day orbit · 1.1 R⊕
- TRAPPIST-1 d 4.05-day orbit · 0.788 R⊕
- TRAPPIST-1 e 6.1-day orbit · 0.92 R⊕
- TRAPPIST-1 f 9.21-day orbit · 1.05 R⊕
- TRAPPIST-1 g 12.4-day orbit · 1.13 R⊕
- TRAPPIST-1 h 18.8-day orbit · 0.755 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.