Exoplanet · gas giant
HD 17156 b
HD 17156 b is a gas giant orbiting the star Nushagak. Its year lasts 21.2 Earth days. It was discovered in 2007 by the Radial Velocity method.
| Host star | Nushagak |
|---|---|
| Distance | 254.7 light-years (78.1 pc) |
| Orbital period | 21.2 days |
| Orbital radius | 0.163 AU |
| Eccentricity | 0.677 |
| Radius | 12.3 R⊕ · 1.09 R♃ |
| Mass | 1,040 M⊕ · 3.26 M♃ |
| Density | 3.08 g/cm³ |
| Surface gravity | 6.89 × Earth |
| Equilibrium temperature | 888 K (615 °C) |
| Stellar flux received | 68.8 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2007 |
| Discovered by | Subaru Telescope |
Habitable zone
Inside the inner edge of the habitable zone: it receives 68.8 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 5° across: 9.3 times the Sun as we see it from Earth.
In the sky
Too faint for the naked eye (magnitude 8.17); binoculars will find it. Visible from the whole Northern Hemisphere and south to latitude 18° S. North of latitude 18° N it never sets. It stands highest at midnight in October, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1771. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 4.5 million years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.