VHS J125601.92-125723.9 b
Astrophysical Synthesis & Habitability Characterization
VHS J125601.92-125723.9 b is a confirmed gas giant exoplanet orbiting the star VHS J125601.92-125723.9, located approximately 41.4 light-years (12.7 parsecs) from the Solar System. First announced in 2015 by Paranal Observatory using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 13.675 Earth radii (1.22 Jupiter radii) and has a measured mass of 5085.255 Earth masses (16 Jupiter masses). Combining its mass and radius yields a mean bulk density of 10.96 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 27.19 g⊕ (266.64 m/s²), and an escape velocity of 215.7 km/s.
In its orbital architecture around VHS J125601.92-125723.9, VHS J125601.92-125723.9 b completes one full revolution every 5800000 Earth days (15879.53Julian years) at a semi-major axis of 350 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 0.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.68, swinging from 112 AU at periapsis out to 588 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1194 K (+921°C / +1690°F), VHS J125601.92-125723.9 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star VHS J125601.92-125723.9 is classified as a low-mass red dwarf of spectral type M7.5 with an effective photospheric temperature of 2,620 K, a mass of 0.07 M☉. Stellar evolution modeling indicates an estimated stellar age of 0.14 Gyr. From Earth, VHS J125601.92-125723.9 shines at apparent V-band magnitude 17.73 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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: Paranal Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | VHS J125601.92-125723.9 |
| Spectral Type | M7.5 |
| Effective Temp (Teff) | 2,620 K |
| Stellar Radius | — |
| Stellar Mass | 0.0700 M☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 0.140 Gyr |
| Apparent Magnitude | V: 17.730 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 350.000000 AU |
| Orbital Period | 5800000 days |
| Mean Orbital Velocity | 0.7 km/s |
| Orbital Eccentricity (e) | 0.68000 |
| Orbital Inclination (i) | 24.0000° |
| Mean Bulk Density | 10.96 g/cm³ (215.7 km/s vesc) |
| Insolation Flux | 0.0000 S⊕ |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 41.400 LY (12.700 pc) |