TOI-707 b
Astrophysical Synthesis & Habitability Characterization
TOI-707 b is a confirmed sub-neptune exoplanet orbiting the star TOI-707, located approximately 427.1 light-years (130.96 parsecs) from the Solar System. First announced in 2026 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.0513% across the stellar disk), this world measures 2.416 Earth radii and has a measured mass of 6.42 Earth masses. Combining its mass and radius yields a mean bulk density of 2.51 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 18.2 km/s.
In its orbital architecture around TOI-707, TOI-707 b completes one full revolution every 52.799 Earth days at a semi-major axis of 0.275 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 56.7 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 492 K (+219°C / +426°F) and receiving 10.97 S⊕ (~14,933 W/m²), TOI-707 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-707 is classified as a stellar host with an effective photospheric temperature of 5,424 K, a radius of 0.978 R☉, a mass of 0.99 M☉, an estimated bolometric luminosity of 0.743 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.6 Gyr and a metallicity of [Fe/H] = 0.16 dex (metal-rich relative to the Sun). From Earth, TOI-707 shines at apparent V-band magnitude 10.71 (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-707 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,424 K |
| Stellar Radius | 0.9780 R☉ |
| Stellar Mass | 0.9900 M☉ |
| Bolometric Luminosity | 0.743 L☉ |
| Metallicity [Fe/H] | 0.160 dex |
| Stellar Age | 0.600 Gyr |
| Apparent Magnitude | V: 10.710 · G: 10.589 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.275000 AU |
| Orbital Period | 52.799 days |
| Mean Orbital Velocity | 56.7 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.6020° |
| Mean Bulk Density | 2.51 g/cm³ (18.2 km/s vesc) |
| Insolation Flux | 10.9718 S⊕ (~14,933 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 427.100 LY (130.959 pc) |