Exoplanet · mini-Neptune
55 Cnc B c
55 Cnc B c is a mini-Neptune orbiting the star 55 Cnc B. Its year lasts 33.7 Earth days. It was discovered in 2025 by the Radial Velocity method.
| Host star | 55 Cnc B |
|---|---|
| Distance | 40.7 light-years (12.5 pc) |
| Orbital period | 33.7 days |
| Orbital radius | 0.13 AU |
| Eccentricity | 0.000 |
| Radius | 2.16 R⊕ · 0.193 R♃ |
| Mass (minimum) | 5.3 M⊕ · 0.0167 M♃ |
| Density | 2.89 g/cm³ |
| Equilibrium temperature | 230 K (-43 °C) |
| Stellar flux received | 0.461 × Earth |
| Discovery method | Radial Velocity |
| Discovery year | 2025 |
| Discovered by | Mauna Kea 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 13.14. Visible from the whole Northern Hemisphere and south to latitude 62° S. North of latitude 62° N it never sets. It stands highest at midnight in January, the best time to observe it.
Light's journey
The light you see tonight set out around the year 1985. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 722 thousand years.
Planets in the same system
- 55 Cnc B b 6.8-day orbit · 1.69 R⊕
Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.