Exoplanet · mini-Neptune
HD 191939 g
HD 191939 g is a mini-Neptune orbiting the star HD 191939. Its year lasts 284 Earth days. It was discovered in 2022 by the Radial Velocity method.
| Host star | HD 191939 |
|---|---|
| Distance | 174.9 light-years (53.6 pc) |
| Orbital period | 284 days |
| Orbital radius | 0.812 AU |
| Eccentricity | 0.030 |
| Radius | 3.74 R⊕ · 0.334 R♃ |
| Mass (minimum) | 13.5 M⊕ · 0.0425 M♃ |
| Density | 1.42 g/cm³ |
| Equilibrium temperature | 278 K (5 °C) |
| Stellar flux received | 0.99 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2022 |
| Discovered by | Multiple Observatories |
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 0.62° across: 1.2 times the Sun as we see it from Earth.
In the sky
Too faint for the naked eye (magnitude 8.97); binoculars will find it. Visible from the whole Northern Hemisphere and south to latitude 23° S. North of latitude 23° N it never sets. It stands highest at midnight in July, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1851. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 3.1 million years.
Planets in the same system
- HD 191939 b 8.88-day orbit · 3.41 R⊕
- HD 191939 c 28.6-day orbit · 3.2 R⊕
- HD 191939 d 38.4-day orbit · 3 R⊕
- HD 191939 e 101-day orbit · 13 R⊕
- HD 191939 f 2,900-day orbit · 13.2 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.