bet UMi b
bet UMi b is a cold gas giant orbiting the K4 III star bet UMi in the constellation Ursa Minor. It lies about 127 light-years from Earth and was discovered in 2014 using the radial velocity method.
Is bet UMi b in the Habitable Zone?
bet UMi b orbits inside the inner edge of the habitable zone of bet UMi. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of bet UMi: 18.741–47.139 AU (conservative: 23.738–44.691 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 ›
Orbit and Year Length
A year on bet UMi b — one full orbit around bet UMi — lasts 522.3 Earth days, longer than an Earth year. It orbits at an average distance of 1.400 AU. Its orbit is mildly elliptical (eccentricity 0.19).
How Was bet UMi b Discovered?
bet UMi b was discovered in 2014 using the radial velocity method, with observations from Bohyunsan Optical Astronomical 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 bet UMi b?
bet UMi b is 126.5 light-years (38.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1900. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,226,400 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. bet UMi b scores 0.07, ranking #4,820 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: bet UMi
bet UMi
- Spectral type
- K4 III
- Surface temperature
- 4,126 K (Sun: 5,772 K)
- Mass
- 1.40 M☉
- Radius
- 38.30 R☉
- Luminosity
- 537.0318 L☉
- Age
- 3.0 billion years (Sun: 4.6)
Planetary System
bet UMi b is the only planet known to orbit bet UMi so far.
bet UMi b — Complete Data
| Mass (best estimate) | 1,938.70 Earth masses |
|---|---|
| Orbital period | 522.30 days |
| Orbital distance | 1.400 AU |
| Eccentricity | 0.190 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 126.5 light-years (38.8 parsecs) |
| Constellation | Ursa Minor |
| Discovery method | Radial Velocity |
| Discovery facility | Bohyunsan Optical Astronomical Observatory |
| Discovery year | 2014 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About bet UMi b
Is bet UMi b habitable?
No — bet UMi b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is bet UMi b?
bet UMi b is about 127 light-years from Earth in the constellation Ursa Minor. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,226,400 years to get there.
How long is a year on bet UMi b?
One orbit around bet UMi takes 522.3 Earth days.
Explore bet UMi b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
