TOI-4479 b
Astrophysical Synthesis & Habitability Characterization
TOI-4479 b is a confirmed sub-neptune exoplanet orbiting the star TOI-4479, located approximately 263.1 light-years (80.65 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 0.3286% across the stellar disk), this world measures 2.82 Earth radii and has a measured mass of 8.35 Earth masses. Combining its mass and radius yields a mean bulk density of 2.05 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.05 g⊕ (10.3 m/s²), and an escape velocity of 19.2 km/s.
In its orbital architecture around TOI-4479, TOI-4479 b completes one full revolution every 1.159 Earth days at a semi-major axis of 0.0164 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 154 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 861 K (+588°C / +1090°F) and receiving 92.50 S⊕ (~125,893 W/m²), TOI-4479 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4479 is classified as a low-mass red dwarf of spectral type M3.0 with an effective photospheric temperature of 3,400 K, a radius of 0.451 R☉, a mass of 0.452 M☉, an estimated bolometric luminosity of 0.024 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, TOI-4479 shines at apparent V-band magnitude 15.18 (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-4479 |
| Spectral Type | M3.0 |
| Effective Temp (Teff) | 3,400 K |
| Stellar Radius | 0.4510 R☉ |
| Stellar Mass | 0.4520 M☉ |
| Bolometric Luminosity | 0.024 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 15.180 · G: 14.131 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.016400 AU |
| Orbital Period | 1.159 days |
| Mean Orbital Velocity | 154 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 86.3600° |
| Mean Bulk Density | 2.05 g/cm³ (19.2 km/s vesc) |
| Insolation Flux | 92.5000 S⊕ (~125,893 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 263.100 LY (80.653 pc) |