55 Cnc B is 40.7 light-years from the Sun. The NASA Exoplanet Archive lists 2 planets around this M4.5 V star; the first was found in 2025 by radial velocity (Mauna Kea Observatory).
Fly there in 3D55 Cnc B b goes round its star every 6.80 days, 13 times as often as Mercury goes round the Sun.
55 Cnc B is one of 2 stars in its system: the other is drawn where the Washington Double Star Catalog measures it on the sky.
| Spectral type | M4.5 V |
| Surface temperature | 3,286 K |
| Mass | 0.26 solar masses |
| Radius | 0.274 solar radii |
| Luminosity | 0.007796 times the Sun |
| Apparent magnitude | 13.152 |
| Age | about 10 billion years |
| Distance from the Sun | 40.7 light-years (12.5 parsecs) |
| Position (J2000) | RA 133.1679°, Dec 28.3153° |
| Constellation | Cancer |
55 Cnc A is a G8V star of magnitude 6.04, judged a true companion. In 2016 it was 84.8″ from 55 Cnc B, at position angle 308° (Washington Double Star Catalog, 08526+2820 LDS6219): 1,058 AU on the sky at this distance. The true distance can only be larger.
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| 55 Cnc B b | 6.80 days | 0.0440 AU | 1.69 R⊕ estimated | 3.5 M⊕ minimum | Radial Velocity, 2025 |
| 55 Cnc B c | 33.7 days | 0.130 AU | 2.16 R⊕ estimated | 5.3 M⊕ minimum | Radial Velocity, 2025 |
Values are the NASA Exoplanet Archive’s composite parameters. A radius marked estimated comes from a mass–radius relation; a mass marked minimum is M sin i. Planet sizes and colours in the 3D view are renderings: none of these worlds has been photographed as more than a point of light.