TOI-871 b
Astrophysical Synthesis & Habitability Characterization
TOI-871 b is a confirmed super-earth exoplanet orbiting the star TOI-871, located approximately 221.9 light-years (68.05 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.045% across the stellar disk), this world measures 1.664 Earth radii and has a measured mass of 3.41 Earth masses. Combining its mass and radius yields a mean bulk density of 4.08 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.23 g⊕ (12.06 m/s²), and an escape velocity of 16 km/s.
In its orbital architecture around TOI-871, TOI-871 b completes one full revolution every 14.363 Earth days at a semi-major axis of 0.1054 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 79.8 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 621 K (+348°C / +658°F) and receiving 24.78 S⊕ (~33,726 W/m²), TOI-871 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-871 is classified as a stellar host with an effective photospheric temperature of 4,929 K, a radius of 0.719 R☉, a mass of 0.758 M☉, an estimated bolometric luminosity of 0.274 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.9 Gyr and a metallicity of [Fe/H] = -0.07 dex (near-solar heavy-element abundance). From Earth, TOI-871 shines at apparent V-band magnitude 10.569 (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-871 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,929 K |
| Stellar Radius | 0.7190 R☉ |
| Stellar Mass | 0.7580 M☉ |
| Bolometric Luminosity | 0.274 L☉ |
| Metallicity [Fe/H] | -0.070 dex |
| Stellar Age | 5.900 Gyr |
| Apparent Magnitude | V: 10.569 · G: 10.345 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.105400 AU |
| Orbital Period | 14.363 days |
| Mean Orbital Velocity | 79.8 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.2600° |
| Mean Bulk Density | 4.08 g/cm³ (16 km/s vesc) |
| Insolation Flux | 24.7800 S⊕ (~33,726 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 221.900 LY (68.047 pc) |