70 Vir b
Astrophysical Synthesis & Habitability Characterization
70 Vir b is a confirmed gas giant exoplanet orbiting the star 70 Vir, located approximately 58.4 light-years (17.9 parsecs) from the Solar System. First announced in 1996 by Lick Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.6 Earth radii (1.12 Jupiter radii) and has a measured mass of 2380.45 Earth masses (7.49 Jupiter masses). Combining its mass and radius yields a mean bulk density of 6.56 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 14.99 g⊕ (147 m/s²), and an escape velocity of 153.8 km/s.
In its orbital architecture around 70 Vir, 70 Vir b completes one full revolution every 116.688 Earth days at a semi-major axis of 0.481 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 44.8 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.3988, swinging from 0.2892 AU at periapsis out to 0.6728 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 525 K (+252°C / +486°F) and receiving 12.22 S⊕ (~16,629 W/m²), 70 Vir b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star 70 Vir is classified as a solar-type yellow star of spectral type G5V with an effective photospheric temperature of 5,495 K, a radius of 1.89 R☉, a mass of 1.09 M☉, an estimated bolometric luminosity of 2.922 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.77 Gyr and a metallicity of [Fe/H] = -0.09 dex (near-solar heavy-element abundance). From Earth, 70 Vir shines at apparent V-band magnitude 4.968 (visible to the unaided human eye under dark skies) in the Northern celestial hemisphere.
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: Lick Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | 70 Vir |
| Spectral Type | G5V |
| Effective Temp (Teff) | 5,495 K |
| Stellar Radius | 1.8900 R☉ |
| Stellar Mass | 1.0900 M☉ |
| Bolometric Luminosity | 2.922 L☉ |
| Metallicity [Fe/H] | -0.090 dex |
| Stellar Age | 7.770 Gyr |
| Apparent Magnitude | V: 4.968 · G: 4.762 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.481000 AU |
| Orbital Period | 116.688 days |
| Mean Orbital Velocity | 44.8 km/s |
| Orbital Eccentricity (e) | 0.39880 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 6.56 g/cm³ (153.8 km/s vesc) |
| Insolation Flux | 12.2183 S⊕ (~16,629 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 58.400 LY (17.901 pc) |