TOI-880 c
Astrophysical Synthesis & Habitability Characterization
TOI-880 c is a confirmed sub-neptune exoplanet orbiting the star TOI-880, located approximately 197.9 light-years (60.67 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 0.2989% across the stellar disk), this world measures 4.95 Earth radii (0.44 Jupiter radii) and has a measured mass of 21.7 Earth masses. Combining its mass and radius yields a mean bulk density of 0.99 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.89 g⊕ (8.73 m/s²), and an escape velocity of 23.4 km/s.
In its orbital architecture around TOI-880, TOI-880 c completes one full revolution every 6.387 Earth days at a semi-major axis of 0.0635 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 108.2 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 805 K (+532°C / +990°F) and receiving 74.00 S⊕ (~100,710 W/m²), TOI-880 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-880 is classified as an orange K-type star of spectral type K with an effective photospheric temperature of 5,050 K, a radius of 0.83 R☉, a mass of 0.87 M☉, an estimated bolometric luminosity of 0.402 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.2 Gyr and a metallicity of [Fe/H] = 0.23 dex (metal-rich relative to the Sun). From Earth, TOI-880 shines at apparent V-band magnitude 10.104 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The TOI-880 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-880 c sharing its stellar neighborhood alongside TOI-880.02.
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-880 |
| Spectral Type | K |
| Effective Temp (Teff) | 5,050 K |
| Stellar Radius | 0.8300 R☉ |
| Stellar Mass | 0.8700 M☉ |
| Bolometric Luminosity | 0.402 L☉ |
| Metallicity [Fe/H] | 0.230 dex |
| Stellar Age | 5.200 Gyr |
| Apparent Magnitude | V: 10.104 · G: 9.837 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.063500 AU |
| Orbital Period | 6.387 days |
| Mean Orbital Velocity | 108.2 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 88.2000° |
| Mean Bulk Density | 0.99 g/cm³ (23.4 km/s vesc) |
| Insolation Flux | 73.9967 S⊕ (~100,710 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 197.900 LY (60.668 pc) |