omi UMa b
omi UMa b is a cold gas giant orbiting the G4 II-III star omi UMa in the constellation Ursa Major. It lies about 179 light-years from Earth and was discovered in 2012 using the radial velocity method.
Is omi UMa b in the Habitable Zone?
omi UMa b orbits inside the inner edge of the habitable zone of omi UMa. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of omi UMa: 8.388–20.221 AU (conservative: 10.625–19.171 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Orbit and Year Length
A year on omi UMa b — one full orbit around omi UMa — lasts 1,569.8 Earth days, longer than an Earth year. It orbits at an average distance of 3.691 AU. Its orbit is mildly elliptical (eccentricity 0.15).
How Was omi UMa b Discovered?
omi UMa b was discovered in 2012 using the radial velocity method, with observations from Okayama Astrophysical 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 omi UMa b?
omi UMa b is 179.1 light-years (54.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1847. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 3,152,160 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. omi UMa b scores 0.18, ranking #4,064 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: omi UMa
omi UMa b belongs to a system of 2 stars; it orbits omi UMa.
omi UMa
- Spectral type
- G4 II-III
- Surface temperature
- 5,075 K (Sun: 5,772 K)
- Mass
- 2.72 M☉
- Radius
- 13.84 R☉
- Luminosity
- 115.5208 L☉
Planetary System
omi UMa b is the only planet known to orbit omi UMa so far.
omi UMa b — Complete Data
| Mass (best estimate) | 1,160.39 Earth masses |
|---|---|
| Orbital period | 1,569.81 days |
| Orbital distance | 3.691 AU |
| Eccentricity | 0.149 |
| Earth Similarity Index | 0.18 |
| Distance from Earth | 179.1 light-years (54.9 parsecs) |
| Constellation | Ursa Major |
| Discovery method | Radial Velocity |
| Discovery facility | Okayama Astrophysical Observatory |
| Discovery year | 2012 |
Data: NASA Exoplanet Archive, last updated 2023-09-19. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About omi UMa b
Is omi UMa b habitable?
No — omi UMa b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is omi UMa b?
omi UMa b is about 179 light-years from Earth in the constellation Ursa Major. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 3,152,160 years to get there.
How long is a year on omi UMa b?
One orbit around omi UMa takes 1,569.8 Earth days.
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