Exoplanet · gas giant
Kepler-817 b
Kepler-817 b is a gas giant orbiting the star Kepler-817. Its year lasts 3.99 Earth days. It was discovered in 2016 by the Transit method.
| Host star | Kepler-817 |
|---|---|
| Distance | 4,842 light-years (1,484 pc) |
| Orbital period | 3.99 days |
| Orbital radius | 0.0493 AU |
| Eccentricity | 0.000 |
| Radius | 9.03 R⊕ · 0.806 R♃ |
| Mass | 60.2 M⊕ · 0.189 M♃ (estimated from the radius) |
| Density | 0.449 g/cm³ |
| Equilibrium temperature | 1,124 K (851 °C) |
| Stellar flux received | 550 × Earth |
| Discovery method | Transit |
| Discovery year | 2016 |
| Discovered by | Kepler |
Habitable zone
Inside the inner edge of the habitable zone: it receives 550 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 11° across: 21 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 15.97. Visible from the whole Northern Hemisphere and south to latitude 51° S. North of latitude 51° 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 4,842 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 86 million years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.