The 55 Cnc B System
55 Cnc B is a planetary system in the constellation Cancer hosting 2 confirmed exoplanets around 2 stars, about 41 light-years from Earth. One of its planets orbits within the habitable zone, where liquid water could exist on a planetary surface.
Star 55 Cnc B and Its Habitable Zone
55 Cnc B
- Spectral type
- M4.5 V
- Surface temperature
- 3,286 K (Sun: 5,772 K)
- Mass
- 0.26 M☉
- Radius
- 0.27 R☉
- Age
- 10.0 billion years (Sun: 4.6)
Habitable zone of 55 Cnc B: 0.073–0.191 AU (conservative: 0.092–0.181 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
All 2 Planets in the 55 Cnc B System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| 55 Cnc B b | Super Earth | 6.8 d | — | — | 2025 |
| 55 Cnc B c HZ | Super Earth | 34 d | — | — | 2025 |
Discovery History
The first planet found here, 55 Cnc B b, was discovered in 2025 using the radial velocity method.
- 2025 — 55 Cnc B b (Radial Velocity)
- 2025 — 55 Cnc B c (Radial Velocity)
Frequently Asked Questions About 55 Cnc B
How many planets does 55 Cnc B have?
55 Cnc B has 2 confirmed exoplanets distributed around its 2 stars. More may await discovery.
Are any planets in the 55 Cnc B system habitable?
One planet in the system orbits within the habitable zone, where liquid water could exist. Actual habitability depends on atmospheres and composition, which are not yet known.
How far away is 55 Cnc B?
55 Cnc B is about 41 light-years from Earth in the constellation Cancer.
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