nu Oph b
nu Oph b is a exoplanet orbiting the K0 III star nu Oph in the constellation Ophiuchus. It lies about 151 light-years from Earth and was discovered in 2012 using the radial velocity method.
Is nu Oph b in the Habitable Zone?
nu Oph b orbits inside the inner edge of the habitable zone of nu Oph. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of nu Oph: 6.975–16.942 AU (conservative: 8.835–16.063 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 nu Oph b — one full orbit around nu Oph — lasts 529.9 Earth days, longer than an Earth year. It orbits at an average distance of 1.765 AU. Its orbit is mildly elliptical (eccentricity 0.13).
How Was nu Oph b Discovered?
nu Oph 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 nu Oph b?
nu Oph b is 150.7 light-years (46.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1876. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,652,320 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. nu Oph b scores 0.11, ranking #4,357 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: nu Oph
nu Oph
- Spectral type
- K0 III
- Surface temperature
- 4,887 K (Sun: 5,772 K)
- Mass
- 2.61 M☉
- Radius
- 12.24 R☉
- Luminosity
- 78.4802 L☉
The nu Oph Planetary System
nu Oph b is one of 2 known planets in the nu Oph system. Its siblings:
nu Oph b — Complete Data
| Mass (best estimate) | 6,848.57 Earth masses |
|---|---|
| Orbital period | 529.93 days |
| Orbital distance | 1.765 AU |
| Eccentricity | 0.126 |
| Earth Similarity Index | 0.11 |
| Distance from Earth | 150.7 light-years (46.2 parsecs) |
| Constellation | Ophiuchus |
| 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 nu Oph b
Is nu Oph b habitable?
No — nu Oph b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is nu Oph b?
nu Oph b is about 151 light-years from Earth in the constellation Ophiuchus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,652,320 years to get there.
How long is a year on nu Oph b?
One orbit around nu Oph takes 529.9 Earth days.
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