Exoplanet · mini-Neptune
GJ 3942 b
GJ 3942 b is a mini-Neptune orbiting the star GJ 3942. Its year lasts 6.91 Earth days. It was discovered in 2017 by the Radial Velocity method.
| Host star | GJ 3942 |
|---|---|
| Distance | 55.2 light-years (16.9 pc) |
| Orbital period | 6.91 days |
| Orbital radius | 0.0608 AU |
| Eccentricity | 0.121 |
| Radius | 2.57 R⊕ · 0.229 R♃ |
| Mass (minimum) | 7.14 M⊕ · 0.0225 M♃ |
| Density | 2.31 g/cm³ |
| Equilibrium temperature | 590 K (317 °C) |
| Stellar flux received | 20.5 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2017 |
| Discovered by | Roque de los Muchachos Observatory |
Habitable zone
Inside the inner edge of the habitable zone: it receives 20.5 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 5.3° 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 10.24. Visible from the whole Northern Hemisphere and south to latitude 37° S. North of latitude 37° N it never sets. It stands highest at midnight in May, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1971. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 979 thousand years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.