Exoplanet · mini-Neptune
Kepler-666 b
Kepler-666 b is a mini-Neptune orbiting the star Kepler-666. Its year lasts 4.5 Earth days. It was discovered in 2016 by the Transit method.
| Host star | Kepler-666 |
|---|---|
| Distance | 4,921 light-years (1,509 pc) |
| Orbital period | 4.5 days |
| Orbital radius | 0.0542 AU |
| Eccentricity | 0.000 |
| Radius | 2.4 R⊕ · 0.214 R♃ |
| Mass | 6.35 M⊕ · 0.02 M♃ (estimated from the radius) |
| Density | 2.52 g/cm³ |
| Equilibrium temperature | 1,133 K (860 °C) |
| Stellar flux received | 576 × Earth |
| Discovery method | Transit |
| Discovery year | 2016 |
| Discovered by | Kepler |
Habitable zone
Inside the inner edge of the habitable zone: it receives 576 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 10° across: 19 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 15.42. Visible from the whole Northern Hemisphere and south to latitude 41° S. North of latitude 41° N it never sets. It stands highest at midnight in July, the best time to observe it.
Light's journey
The light you see tonight set out 4,921 years ago. At that time the first farming villages were being founded; there was no writing yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 87 million years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.