TOI-4155 b
Astrophysical Synthesis & Habitability Characterization
TOI-4155 b is a confirmed sub-neptune exoplanet orbiting the star TOI-4155, located approximately 785.2 light-years (240.74 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 0.096% across the stellar disk), this world measures 3.21 Earth radii (0.29 Jupiter radii) and has a measured mass of 10.4 Earth masses. Combining its mass and radius yields a mean bulk density of 1.73 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.01 g⊕ (9.9 m/s²), and an escape velocity of 20.1 km/s.
In its orbital architecture around TOI-4155, TOI-4155 b completes one full revolution every 3.321 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1255 K (+982°C / +1800°F) and receiving 586.76 S⊕ (~798,583 W/m²), TOI-4155 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4155 is classified as a stellar host with an effective photospheric temperature of 5,724 K, a radius of 0.95 R☉, a mass of 1.16 M☉, an estimated bolometric luminosity of 0.869 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.11 dex (metal-rich relative to the Sun). From Earth, TOI-4155 shines at apparent V-band magnitude 11.85 (faint and requiring research-grade or CCD telescopic photometry) in the Northern 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-4155 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,724 K |
| Stellar Radius | 0.9500 R☉ |
| Stellar Mass | 1.1600 M☉ |
| Bolometric Luminosity | 0.869 L☉ |
| Metallicity [Fe/H] | 0.110 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 11.850 · G: 11.690 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 3.321 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 88.8400° |
| Mean Bulk Density | 1.73 g/cm³ (20.1 km/s vesc) |
| Insolation Flux | 586.7620 S⊕ (~798,583 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 785.200 LY (240.737 pc) |