TOI-431 c
Astrophysical Synthesis & Habitability Characterization
TOI-431 c is a confirmed super-earth exoplanet orbiting the star TOI-431, located approximately 106.2 light-years (32.57 parsecs) from the Solar System. First announced in 2021 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 1.49 Earth radii and has a measured mass of 2.83 Earth masses. Combining its mass and radius yields a mean bulk density of 4.72 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.27 g⊕ (12.45 m/s²), and an escape velocity of 15.4 km/s.
In its orbital architecture around TOI-431, TOI-431 c completes one full revolution every 4.849 Earth days at a semi-major axis of 0.052 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 116.7 km/s (compared to Earth's 29.8 km/s). 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 867 K (+594°C / +1101°F) and receiving 100.67 S⊕ (~137,014 W/m²), TOI-431 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-431 is classified as a stellar host with an effective photospheric temperature of 4,850 K, a radius of 0.731 R☉, a mass of 0.78 M☉, an estimated bolometric luminosity of 0.265 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.2 dex (metal-rich relative to the Sun). From Earth, TOI-431 shines at apparent V-band magnitude 9.12 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The TOI-431 system is a multi-planet architecture hosting 3 confirmed worlds, with TOI-431 c sharing its stellar neighborhood alongside TOI-431 b, TOI-431 d.
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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | TOI-431 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,850 K |
| Stellar Radius | 0.7310 R☉ |
| Stellar Mass | 0.7800 M☉ |
| Bolometric Luminosity | 0.265 L☉ |
| Metallicity [Fe/H] | 0.200 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 9.120 · G: 8.792 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.052000 AU |
| Orbital Period | 4.849 days |
| Mean Orbital Velocity | 116.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.3500° |
| Mean Bulk Density | 4.72 g/cm³ (15.4 km/s vesc) |
| Insolation Flux | 100.6717 S⊕ (~137,014 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 106.200 LY (32.569 pc) |