Exoplanet · gas giant
HD 81817 b
HD 81817 b is a gas giant orbiting the star HD 81817. Its year lasts 1,020 Earth days. It was discovered in 2020 by the Radial Velocity method.
| Host star | HD 81817 |
|---|---|
| Distance | 877.8 light-years (269.1 pc) |
| Orbital period | 2.8 years |
| Orbital radius | 3.23 AU |
| Eccentricity | 0.097 |
| Radius | 12 R⊕ · 1.07 R♃ |
| Mass | 7,670 M⊕ · 24.1 M♃ |
| Density | 24.4 g/cm³ |
| Surface gravity | 53.3 × Earth |
| Equilibrium temperature | 1,016 K (743 °C) |
| Stellar flux received | 174 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2020 |
| Discovered by | Bohyunsan Optical Astronomical Observatory |
Habitable zone
Inside the inner edge of the habitable zone: it receives 174 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 14° across: 26 times the Sun as we see it from Earth.
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.28). Visible from the whole Northern Hemisphere and south to latitude 9° S. North of latitude 9° N it never sets.
Light's journey
The light you see tonight set out around the year 1148. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 16 million years.
Planets in the same system
- HD 81817 c 623-day orbit · 12 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.