TOI-880.02
Astrophysical Synthesis & Habitability Characterization
TOI-880.02 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 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.0585% across the stellar disk), this world measures 2.19 Earth radii and has a measured mass of 5.43 Earth masses. Combining its mass and radius yields a mean bulk density of 2.85 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.13 g⊕ (11.08 m/s²), and an escape velocity of 17.6 km/s.
In its orbital architecture around TOI-880, TOI-880.02 completes one full revolution every 2.576 Earth days at a semi-major axis of 0.0349 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 147.4 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1085 K (+812°C / +1494°F) and receiving 301.87 S⊕ (~410,840 W/m²), TOI-880.02 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-880.02 sharing its stellar neighborhood alongside TOI-880 c.
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) | 0.034900 AU |
| Orbital Period | 2.576 days |
| Mean Orbital Velocity | 147.4 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 87.8000° |
| Mean Bulk Density | 2.85 g/cm³ (17.6 km/s vesc) |
| Insolation Flux | 301.8661 S⊕ (~410,840 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 197.900 LY (60.668 pc) |