TOI-6628 b
Astrophysical Synthesis & Habitability Characterization
TOI-6628 b is a confirmed gas giant exoplanet orbiting the star TOI-6628, located approximately 1045.4 light-years (320.53 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 0.9943% across the stellar disk), this world measures 10.985 Earth radii (0.98 Jupiter radii) and has a measured mass of 235.193 Earth masses (0.74 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.98 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.95 g⊕ (19.12 m/s²), and an escape velocity of 51.8 km/s.
In its orbital architecture around TOI-6628, TOI-6628 b completes one full revolution every 18.184 Earth days at a semi-major axis of 0.134 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 80.2 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.67, swinging from 0.0442 AU at periapsis out to 0.2238 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 833 K (+560°C / +1040°F) and receiving 20.09 S⊕ (~27,337 W/m²), TOI-6628 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-6628 is classified as a stellar host with an effective photospheric temperature of 5,463 K, a radius of 1.01 R☉, a mass of 0.97 M☉, an estimated bolometric luminosity of 0.815 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.5 Gyr and a metallicity of [Fe/H] = 0.36 dex (metal-rich relative to the Sun). From Earth, TOI-6628 shines at apparent V-band magnitude 12.9 (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-6628 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,463 K |
| Stellar Radius | 1.0100 R☉ |
| Stellar Mass | 0.9700 M☉ |
| Bolometric Luminosity | 0.815 L☉ |
| Metallicity [Fe/H] | 0.360 dex |
| Stellar Age | 7.500 Gyr |
| Apparent Magnitude | V: 12.900 · G: 12.641 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.134000 AU |
| Orbital Period | 18.184 days |
| Mean Orbital Velocity | 80.2 km/s |
| Orbital Eccentricity (e) | 0.67000 |
| Orbital Inclination (i) | 88.1900° |
| Mean Bulk Density | 0.98 g/cm³ (51.8 km/s vesc) |
| Insolation Flux | 20.0861 S⊕ (~27,337 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1045.400 LY (320.527 pc) |