NGTS-6 b
Astrophysical Synthesis & Habitability Characterization
NGTS-6 b is a confirmed gas giant exoplanet orbiting the star NGTS-6, located approximately 1005.4 light-years (308.26 parsecs) from the Solar System. First announced in 2019 by Next-Generation Transit Survey (NGTS) using the Transit detection technique (producing an estimated primary transit depth of 3.266% across the stellar disk), this world measures 14.863 Earth radii (1.33 Jupiter radii) and has a measured mass of 425.574 Earth masses (1.34 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.71 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.93 g⊕ (18.93 m/s²), and an escape velocity of 59.9 km/s.
In its orbital architecture around NGTS-6, NGTS-6 b completes one full revolution every 0.882 Earth days at a semi-major axis of 0.01677 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 206.8 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1284 K (+1011°C / +1852°F) and receiving 983.42 S⊕ (~1,338,441 W/m²), NGTS-6 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star NGTS-6 is classified as a stellar host with an effective photospheric temperature of 4,730 K, a radius of 0.754 R☉, a mass of 0.767 M☉, an estimated bolometric luminosity of 0.255 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.77 Gyr and a metallicity of [Fe/H] = 0.11 dex (metal-rich relative to the Sun). From Earth, NGTS-6 shines at apparent V-band magnitude 14.237 (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: Next-Generation Transit Survey (NGTS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | NGTS-6 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,730 K |
| Stellar Radius | 0.7540 R☉ |
| Stellar Mass | 0.7670 M☉ |
| Bolometric Luminosity | 0.255 L☉ |
| Metallicity [Fe/H] | 0.110 dex |
| Stellar Age | 9.770 Gyr |
| Apparent Magnitude | V: 14.237 · G: 13.818 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.016770 AU |
| Orbital Period | 0.882 days |
| Mean Orbital Velocity | 206.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 78.2310° |
| Mean Bulk Density | 0.71 g/cm³ (59.9 km/s vesc) |
| Insolation Flux | 983.4246 S⊕ (~1,338,441 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1005.400 LY (308.262 pc) |