NGTS-34 b

Astrophysical Synthesis & Habitability Characterization

NGTS-34 b is a confirmed sub-neptune exoplanet orbiting the star NGTS-34, located approximately 392.9 light-years (120.48 parsecs) from the Solar System. First announced in 2025 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.0599% across the stellar disk), this world measures 3.65 Earth radii (0.33 Jupiter radii) and has a measured mass of 19.1 Earth masses. Combining its mass and radius yields a mean bulk density of 2.17 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.43 g⊕ (14.02 m/s²), and an escape velocity of 25.6 km/s.

In its orbital architecture around NGTS-34, NGTS-34 b completes one full revolution every 43.127 Earth days at a semi-major axis of 0.257 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 64.8 km/s (compared to Earth's 29.8 km/s).

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 624 K (+351°C / +664°F) and receiving 36.03 S⊕ (~49,042 W/m²), NGTS-34 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star NGTS-34 is classified as a warm F-type star of spectral type F8 V with an effective photospheric temperature of 6,134 K, a radius of 1.367 R☉, a mass of 1.266 M☉, an estimated bolometric luminosity of 2.374 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.7 Gyr and a metallicity of [Fe/H] = 0.228 dex (metal-rich relative to the Sun). From Earth, NGTS-34 shines at apparent V-band magnitude 9.229 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere.

Discovery Facility: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).