TOI-782 b
Astrophysical Synthesis & Habitability Characterization
TOI-782 b is a confirmed sub-neptune exoplanet orbiting the star TOI-782, located approximately 171.3 light-years (52.51 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 0.3683% across the stellar disk), this world measures 2.734 Earth radii and has a measured mass of 19.1 Earth masses. Combining its mass and radius yields a mean bulk density of 5.15 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 2.56 g⊕ (25.11 m/s²), and an escape velocity of 29.6 km/s.
In its orbital architecture around TOI-782, TOI-782 b completes one full revolution every 8.024 Earth days at a semi-major axis of 0.0578 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 78.4 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.19 carries the world between 0.0468 AU at periapsis and 0.0688 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 435 K (+162°C / +324°F) and receiving 5.91 S⊕ (~8,044 W/m²), TOI-782 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-782 is classified as a stellar host with an effective photospheric temperature of 3,370 K, a radius of 0.413 R☉, a mass of 0.397 M☉, an estimated bolometric luminosity of 0.02 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.34 dex (metal-rich relative to the Sun). From Earth, TOI-782 shines at apparent V-band magnitude 14.83 (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-782 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,370 K |
| Stellar Radius | 0.4130 R☉ |
| Stellar Mass | 0.3970 M☉ |
| Bolometric Luminosity | 0.02 L☉ |
| Metallicity [Fe/H] | 0.340 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 14.830 · G: 13.565 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.057800 AU |
| Orbital Period | 8.024 days |
| Mean Orbital Velocity | 78.4 km/s |
| Orbital Eccentricity (e) | 0.19000 |
| Orbital Inclination (i) | 88.9800° |
| Mean Bulk Density | 5.15 g/cm³ (29.6 km/s vesc) |
| Insolation Flux | 5.9100 S⊕ (~8,044 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 171.300 LY (52.512 pc) |