Exoplanet · gas giant
GJ 317 b
GJ 317 b is a gas giant orbiting the star GJ 317. Its year lasts 696 Earth days. It was discovered in 2007 by the Radial Velocity method.
| Host star | GJ 317 |
|---|---|
| Distance | 49.6 light-years (15.2 pc) |
| Orbital period | 696 days |
| Orbital radius | 1.14 AU |
| Eccentricity | 0.083 |
| Radius | 13.3 R⊕ · 1.19 R♃ |
| Mass | 795 M⊕ · 2.5 M♃ |
| Density | 1.86 g/cm³ |
| Surface gravity | 4.49 × Earth |
| Equilibrium temperature | 100 K (-173 °C) |
| Stellar flux received | 0.0159 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2007 |
| Discovered by | W. M. Keck Observatory |
Habitable zone
Beyond the habitable zone: it receives only %1.6 of the light the Earth does, a frozen world.
Its star in the sky
In the planet's sky its star is a disc 0.19° across: 0.35 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 11.98. Visible from the whole Southern Hemisphere and north to latitude 67° N. South of latitude 67° S it never sets. It stands highest at midnight in January, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1976. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 879 thousand years.
Planets in the same system
- GJ 317 c 6,500-day orbit · 13.6 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.