NGTS-13 b
Astrophysical Synthesis & Habitability Characterization
NGTS-13 b is a confirmed gas giant exoplanet orbiting the star NGTS-13, located approximately 2112.2 light-years (647.6 parsecs) from the Solar System. First announced in 2021 by Next-Generation Transit Survey (NGTS) using the Transit detection technique (producing an estimated primary transit depth of 0.4308% across the stellar disk), this world measures 12.801 Earth radii (1.14 Jupiter radii) and has a measured mass of 1538.297 Earth masses (4.84 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.04 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 9.39 g⊕ (92.08 m/s²), and an escape velocity of 122.6 km/s.
In its orbital architecture around NGTS-13, NGTS-13 b completes one full revolution every 4.119 Earth days at a semi-major axis of 0.0549 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 145 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.086 carries the world between 0.0502 AU at periapsis and 0.0596 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1605 K (+1332°C / +2430°F) and receiving 1,096.00 S⊕ (~1,491,656 W/m²), NGTS-13 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star NGTS-13 is classified as a stellar host with an effective photospheric temperature of 5,819 K, a radius of 1.788 R☉, a mass of 1.3 M☉, an estimated bolometric luminosity of 3.289 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.23 Gyr and a metallicity of [Fe/H] = 0.25 dex (metal-rich relative to the Sun). From Earth, NGTS-13 shines at apparent V-band magnitude 12.744 (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-13 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,819 K |
| Stellar Radius | 1.7880 R☉ |
| Stellar Mass | 1.3000 M☉ |
| Bolometric Luminosity | 3.289 L☉ |
| Metallicity [Fe/H] | 0.250 dex |
| Stellar Age | 4.230 Gyr |
| Apparent Magnitude | V: 12.744 · G: 12.569 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.054900 AU |
| Orbital Period | 4.119 days |
| Mean Orbital Velocity | 145 km/s |
| Orbital Eccentricity (e) | 0.08600 |
| Orbital Inclination (i) | 88.7000° |
| Mean Bulk Density | 4.04 g/cm³ (122.6 km/s vesc) |
| Insolation Flux | 1096.0000 S⊕ (~1,491,656 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2112.200 LY (647.595 pc) |