Exoplanet · gas giant
HIP 81991 b
HIP 81991 b is a gas giant orbiting the star HIP 81991. Its year lasts 5,860 Earth days. It was discovered in 2026 by the Radial Velocity method.
| Host star | HIP 81991 |
|---|---|
| Distance | 143.2 light-years (43.9 pc) |
| Orbital period | 16 years |
| Orbital radius | 6.4 AU |
| Radius | 12.5 R⊕ · 1.12 R♃ |
| Mass | 3,020 M⊕ · 9.5 M♃ |
| Density | 8.49 g/cm³ |
| Surface gravity | 19.3 × Earth |
| Equilibrium temperature | 163 K (-110 °C) |
| Stellar flux received | 0.119 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2026 |
| Discovered by | Multiple Facilities |
Habitable zone
Beyond the habitable zone: it receives only %12 of the light the Earth does, a frozen world.
Its star in the sky
In the planet's sky its star is a disc 0.23° across: 0.44 times the Sun as we see it from Earth.
In the sky
Too faint for the naked eye (magnitude 6.55); binoculars will find it. Visible from the whole Northern Hemisphere and south to latitude 84° S. It stands highest at midnight in May, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1883. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.5 million years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.