Exoplanet · mini-Neptune
HN Lib b
HN Lib b is a mini-Neptune orbiting the star HN Lib. Its year lasts 36.1 Earth days. It was discovered in 2023 by the Radial Velocity method.
| Host star | HN Lib |
|---|---|
| Distance | 20.4 light-years (6.24 pc) |
| Orbital period | 36.1 days |
| Orbital radius | 0.142 AU |
| Eccentricity | 0.079 |
| Radius | 2.2 R⊕ · 0.196 R♃ |
| Mass (minimum) | 5.46 M⊕ · 0.0172 M♃ |
| Density | 2.82 g/cm³ |
| Equilibrium temperature | 234 K (-39 °C) |
| Stellar flux received | 0.503 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2023 |
| Discovered by | Calar Alto Observatory |
Habitable zone
Inside its star's habitable zone: it receives enough light for liquid water to exist on its surface under a suitable atmosphere.
Its star in the sky
In the planet's sky its star is a disc 1.1° across: 2.1 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 11.32. Visible from the whole Southern Hemisphere and north to latitude 77° N. South of latitude 77° S it never sets. It stands highest at midnight in April, the best time to observe it.
Light's journey
The light you see tonight set out around the year 2006. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 361 thousand years.
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.