TOI-6434 b
Astrophysical Synthesis & Habitability Characterization
TOI-6434 b is a confirmed sub-neptune exoplanet orbiting the star TOI-6434, located approximately 417.5 light-years (128.01 parsecs) from the Solar System. First announced in 2026 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.415% across the stellar disk), this world measures 4.61 Earth radii (0.41 Jupiter radii) and has a measured mass of 19.2 Earth masses. Combining its mass and radius yields a mean bulk density of 1.08 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.9 g⊕ (8.83 m/s²), and an escape velocity of 22.8 km/s.
In its orbital architecture around TOI-6434, TOI-6434 b completes one full revolution every 2.778 Earth days. 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 832 K (+559°C / +1038°F) and receiving 79.81 S⊕ (~108,618 W/m²), TOI-6434 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-6434 is classified as a stellar host with an effective photospheric temperature of 3,982 K, a radius of 0.6561 R☉, a mass of 0.6317 M☉, an estimated bolometric luminosity of 0.097 L☉. From Earth, TOI-6434 shines at apparent V-band magnitude 13.72 (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 | TOI-6434 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,982 K |
| Stellar Radius | 0.6561 R☉ |
| Stellar Mass | 0.6317 M☉ |
| Bolometric Luminosity | 0.097 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 13.720 · G: 13.185 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 2.778 days |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.08 g/cm³ (22.8 km/s vesc) |
| Insolation Flux | 79.8073 S⊕ (~108,618 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 417.500 LY (128.006 pc) |