NGTS-27 b
Astrophysical Synthesis & Habitability Characterization
NGTS-27 b is a confirmed gas giant exoplanet orbiting the star NGTS-27, located approximately 3072.8 light-years (942.12 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.6569% across the stellar disk), this world measures 15.648 Earth radii (1.4 Jupiter radii) and has a measured mass of 188.472 Earth masses (0.59 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.27 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.77 g⊕ (7.55 m/s²), and an escape velocity of 38.8 km/s.
In its orbital architecture around NGTS-27, NGTS-27 b completes one full revolution every 3.37 Earth days at a semi-major axis of 0.0446 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 144 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 1783 K (+1510°C / +2750°F) and receiving 1,680.00 S⊕ (~2,286,480 W/m²), NGTS-27 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star NGTS-27 is classified as a stellar host with an effective photospheric temperature of 5,700 K, a radius of 1.77 R☉, a mass of 1.07 M☉, an estimated bolometric luminosity of 2.967 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.9 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, NGTS-27 shines at apparent V-band magnitude 13.523 (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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | NGTS-27 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,700 K |
| Stellar Radius | 1.7700 R☉ |
| Stellar Mass | 1.0700 M☉ |
| Bolometric Luminosity | 2.967 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 7.900 Gyr |
| Apparent Magnitude | V: 13.523 · G: 13.348 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.044600 AU |
| Orbital Period | 3.37 days |
| Mean Orbital Velocity | 144 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.2000° |
| Mean Bulk Density | 0.27 g/cm³ (38.8 km/s vesc) |
| Insolation Flux | 1680.0000 S⊕ (~2,286,480 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3072.800 LY (942.122 pc) |