Exoplanet · mini-Neptune
HD 224018 d
HD 224018 d is a mini-Neptune orbiting the star HD 224018. Its year lasts 138 Earth days. It was discovered in 2025 by the Transit method.
| Host star | HD 224018 |
|---|---|
| Distance | 344.0 light-years (105.5 pc) |
| Orbital period | 138 days |
| Orbital radius | 0.53 AU |
| Eccentricity | 0.040 |
| Radius | 2.4 R⊕ · 0.214 R♃ |
| Mass | 4.2 M⊕ · 0.0132 M♃ |
| Density | 1.7 g/cm³ |
| Surface gravity | 0.729 × Earth |
| Equilibrium temperature | 411 K (138 °C) |
| Stellar flux received | 4.73 × Earth |
| Discovery method | Transit |
| Discovery year | 2025 |
| Discovered by | K2 |
Habitable zone
Inside the inner edge of the habitable zone: it receives 4.73 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 1.2° across: 2.2 times the Sun as we see it from Earth.
In the sky
A telescope is needed to see it: its apparent magnitude is 9.79. Visible from the whole Southern Hemisphere and north to latitude 85° N. It stands highest at midnight in September, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1682. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 6.1 million years.
Planets in the same system
- HD 224018 b 10.6-day orbit · 0.91 R⊕
- HD 224018 c 36.6-day orbit · 2.42 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.