nu Oph b
Astrophysical Synthesis & Habitability Characterization
nu Oph b is a confirmed gas giant exoplanet orbiting the star nu Oph, located approximately 150.7 light-years (46.21 parsecs) from the Solar System. First announced in 2012 by Okayama Astrophysical Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12 Earth radii (1.07 Jupiter radii) and has a measured mass of 7057.733 Earth masses (22.21 Jupiter masses). Combining its mass and radius yields a mean bulk density of 22.52 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 49.01 g⊕ (480.62 m/s²), and an escape velocity of 271.3 km/s.
In its orbital architecture around nu Oph, nu Oph b completes one full revolution every 529.93 Earth days (1.45Julian years) at a semi-major axis of 1.765 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 36.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.126 carries the world between 1.5426 AU at periapsis and 1.9874 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 621 K (+348°C / +658°F) and receiving 25.19 S⊕ (~34,287 W/m²), nu Oph b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star nu Oph is classified as an orange K-type star of spectral type K0 III with an effective photospheric temperature of 4,887 K, a radius of 12.24 R☉, a mass of 2.61 M☉, an estimated bolometric luminosity of 76.669 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.65 Gyr and a metallicity of [Fe/H] = 0.1 dex (metal-rich relative to the Sun). From Earth, nu Oph shines at apparent V-band magnitude 3.312 (visible to the unaided human eye under dark skies) in the Southern celestial hemisphere. The nu Oph system is a multi-planet architecture hosting 2 confirmed worlds, with nu Oph b sharing its stellar neighborhood alongside nu Oph c.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: Okayama Astrophysical Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | nu Oph |
| Spectral Type | K0 III |
| Effective Temp (Teff) | 4,887 K |
| Stellar Radius | 12.2400 R☉ |
| Stellar Mass | 2.6100 M☉ |
| Bolometric Luminosity | 76.669 L☉ |
| Metallicity [Fe/H] | 0.100 dex |
| Stellar Age | 0.650 Gyr |
| Apparent Magnitude | V: 3.312 · G: 3.097 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.765000 AU |
| Orbital Period | 529.93 days |
| Mean Orbital Velocity | 36.2 km/s |
| Orbital Eccentricity (e) | 0.12600 |
| Orbital Inclination (i) | 90.0000° |
| Mean Bulk Density | 22.52 g/cm³ (271.3 km/s vesc) |
| Insolation Flux | 25.1924 S⊕ (~34,287 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 150.700 LY (46.211 pc) |