Exoplanet · mini-Neptune
Kepler-1539 b
Kepler-1539 b is a mini-Neptune orbiting the star Kepler-1539. Its year lasts 133 Earth days. It was discovered in 2016 by the Transit method.
| Host star | Kepler-1539 |
|---|---|
| Distance | 2,441 light-years (748.3 pc) |
| Orbital period | 133 days |
| Orbital radius | 0.477 AU |
| Eccentricity | 0.000 |
| Radius | 2.7 R⊕ · 0.241 R♃ |
| Mass | 7.75 M⊕ · 0.0244 M♃ (estimated from the radius) |
| Density | 2.16 g/cm³ |
| Equilibrium temperature | 301 K (28 °C) |
| Stellar flux received | 1.57 × Earth |
| Discovery method | Transit |
| Discovery year | 2016 |
| Discovered by | Kepler |
Habitable zone
At the edge of the habitable zone (within the optimistic limits): liquid water would be possible only with a favourable atmosphere.
Its star in the sky
In the planet's sky its star is a disc 0.89° across: 1.7 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 15.49. Visible from the whole Northern Hemisphere and south to latitude 46° S. North of latitude 46° 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 416 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 43 million years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.