rho CrB b
The parameters of this planet are disputed or ambiguous in the scientific literature.
rho CrB b is a cold gas giant orbiting the G0 star rho CrB in the constellation Corona Borealis. It lies about 57 light-years from Earth and was discovered in 1997 using the radial velocity method.
Is rho CrB b in the Habitable Zone?
The position of rho CrB b relative to the habitable zone of rho CrB cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on rho CrB b — one full orbit around rho CrB — lasts 39.8 Earth days, shorter than Mercury's 88-day year. Its orbit is nearly circular (eccentricity 0.046).
How Was rho CrB b Discovered?
rho CrB b was discovered in 1997 using the radial velocity method, with observations from Fred Lawrence Whipple Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is rho CrB b?
rho CrB b is 57.0 light-years (17.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1969. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,003,200 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. rho CrB b scores 0.09, ranking #4,487 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: rho CrB
rho CrB
- Spectral type
- G0
- Mass
- 1.00 M☉
The rho CrB Planetary System
rho CrB b is one of 3 known planets in the rho CrB system. Its siblings:
rho CrB b — Complete Data
| Mass (best estimate) | 348.00 Earth masses |
|---|---|
| Orbital period | 39.85 days |
| Eccentricity | 0.046 |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 57.0 light-years (17.5 parsecs) |
| Constellation | Corona Borealis |
| Discovery method | Radial Velocity |
| Discovery facility | Fred Lawrence Whipple Observatory |
| Discovery year | 1997 |
Data: NASA Exoplanet Archive, last updated 2026-04-23. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About rho CrB b
Is rho CrB b habitable?
rho CrB b is not known to orbit within the habitable zone of rho CrB, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is rho CrB b?
rho CrB b is about 57 light-years from Earth in the constellation Corona Borealis. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,003,200 years to get there.
How long is a year on rho CrB b?
One orbit around rho CrB takes 39.8 Earth days.
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