Exoplanet · Neptune-like planet
Kepler-421 b
Kepler-421 b is a Neptune-like planet orbiting the star Kepler-421. Its year lasts 704 Earth days. It was discovered in 2014 by the Transit method.
| Host star | Kepler-421 |
|---|---|
| Distance | 1,137 light-years (348.6 pc) |
| Orbital period | 704 days |
| Orbital radius | 1.22 AU |
| Eccentricity | 0.041 |
| Radius | 4.16 R⊕ · 0.371 R♃ |
| Mass | 16.1 M⊕ · 0.0507 M♃ (estimated from the radius) |
| Density | 1.23 g/cm³ |
| Equilibrium temperature | 185 K (-88 °C) |
| Stellar flux received | 0.2 × Earth |
| Discovery method | Transit |
| Discovery year | 2014 |
| Discovered by | Kepler |
Habitable zone
Beyond the habitable zone: it receives only %20 of the light the Earth does, a frozen world.
Its star in the sky
In the planet's sky its star is a disc 0.33° across: 0.62 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 13.61. Visible from the whole Northern Hemisphere and south to latitude 45° S. North of latitude 45° 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 around the year 889. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 20 million years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.