Exoplanet · gas giant
BD+20 2457 b
BD+20 2457 b is a gas giant orbiting the star BD+20 2457. Its year lasts 380 Earth days. It was discovered in 2009 by the Radial Velocity method.
| Host star | BD+20 2457 |
|---|---|
| Distance | 5,022 light-years (1,540 pc) |
| Orbital period | 380 days |
| Orbital radius | 1.45 AU |
| Eccentricity | 0.150 |
| Radius | 12.1 R⊕ · 1.08 R♃ |
| Mass (minimum) | 6,810 M⊕ · 21.4 M♃ |
| Density | 21.1 g/cm³ |
| Equilibrium temperature | 1,160 K (887 °C) |
| Stellar flux received | 703 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2009 |
| Discovered by | McDonald Observatory |
Habitable zone
Inside the inner edge of the habitable zone: it receives 703 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 18° across: 34 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 9.88. Visible from the whole Northern Hemisphere and south to latitude 70° S. North of latitude 70° N it never sets. It stands highest at midnight in February, the best time to observe it.
Light's journey
The light you see tonight set out 5,022 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 89 million years.
Planets in the same system
- BD+20 2457 c 622-day orbit · 12.4 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.