TOI-5174 b
Astrophysical Synthesis & Habitability Characterization
TOI-5174 b is a confirmed sub-neptune exoplanet orbiting the star TOI-5174, located approximately 643.3 light-years (197.24 parsecs) from the Solar System. First announced in 2022 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.2009% across the stellar disk), this world measures 5.351 Earth radii (0.48 Jupiter radii) and has a measured mass of 24.8 Earth masses. Combining its mass and radius yields a mean bulk density of 0.89 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.87 g⊕ (8.53 m/s²), and an escape velocity of 24.1 km/s.
In its orbital architecture around TOI-5174, TOI-5174 b completes one full revolution every 12.214 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 808 K (+535°C / +995°F) and receiving 100.91 S⊕ (~137,340 W/m²), TOI-5174 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5174 is classified as a stellar host with an effective photospheric temperature of 5,644 K, a radius of 1.0946 R☉, a mass of 1 M☉, an estimated bolometric luminosity of 1.091 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.415 dex (metal-rich relative to the Sun). From Earth, TOI-5174 shines at apparent V-band magnitude 11.583 (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-5174 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,644 K |
| Stellar Radius | 1.0946 R☉ |
| Stellar Mass | 1.0000 M☉ |
| Bolometric Luminosity | 1.091 L☉ |
| Metallicity [Fe/H] | 0.415 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 11.583 · G: 11.103 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 12.214 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.89 g/cm³ (24.1 km/s vesc) |
| Insolation Flux | 100.9112 S⊕ (~137,340 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 643.300 LY (197.243 pc) |