Exoplanet · gas giant
Kepler-9 b
Kepler-9 b is a gas giant orbiting the star Kepler-9. Its year lasts 19.2 Earth days. It was discovered in 2010 by the Transit method.
| Host star | Kepler-9 |
|---|---|
| Distance | 2,049 light-years (628.3 pc) |
| Orbital period | 19.2 days |
| Orbital radius | 0.143 AU |
| Eccentricity | 0.061 |
| Radius | 8.29 R⊕ · 0.74 R♃ |
| Mass | 43.4 M⊕ · 0.137 M♃ |
| Density | 0.42 g/cm³ |
| Surface gravity | 0.632 × Earth |
| Equilibrium temperature | 661 K (388 °C) |
| Stellar flux received | 48.2 × Earth |
| Discovery method | Transit |
| Discovery year | 2010 |
| Discovered by | Kepler |
Habitable zone
Inside the inner edge of the habitable zone: it receives 48.2 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 3.6° across: 6.7 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 13.92. Visible from the whole Northern Hemisphere and south to latitude 52° S. North of latitude 52° 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 24 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 36 million years.
Planets in the same system
- Kepler-9 d 1.59-day orbit · 1.64 R⊕
- Kepler-9 c 39-day orbit · 8.08 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.