Exoplanet · mini-Neptune
GJ 3138 d
GJ 3138 d is a mini-Neptune orbiting the star GJ 3138. Its year lasts 258 Earth days. It was discovered in 2017 by the Radial Velocity method.
| Host star | GJ 3138 |
|---|---|
| Distance | 92.9 light-years (28.5 pc) |
| Orbital period | 258 days |
| Orbital radius | 0.698 AU |
| Eccentricity | 0.320 |
| Radius | 3.23 R⊕ · 0.288 R♃ |
| Mass (minimum) | 10.5 M⊕ · 0.033 M♃ |
| Density | 1.71 g/cm³ |
| Equilibrium temperature | 152 K (-121 °C) |
| Stellar flux received | 0.1 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2017 |
| Discovered by | La Silla Observatory |
Habitable zone
Beyond the habitable zone: it receives only %10 of the light the Earth does, a frozen world.
Its star in the sky
In the planet's sky its star is a disc 0.38° across: 0.72 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 10.89. Visible from the whole Southern Hemisphere and north to latitude 74° N. South of latitude 74° S it never sets. It stands highest at midnight in October, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1933. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 1.6 million years.
Planets in the same system
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.