TOI-3331 A b
Astrophysical Synthesis & Habitability Characterization
TOI-3331 A b is a confirmed gas giant exoplanet orbiting the star TOI-3331 A, located approximately 708.4 light-years (217.19 parsecs) from the Solar System. First announced in 2022 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 1.5625% across the stellar disk), this world measures 12.98 Earth radii (1.16 Jupiter radii) and has a measured mass of 721.47 Earth masses (2.27 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.82 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 4.28 g⊕ (41.97 m/s²), and an escape velocity of 83.4 km/s.
In its orbital architecture around TOI-3331 A, TOI-3331 A b completes one full revolution every 2.018 Earth days at a semi-major axis of 0.03144 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 169.5 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1488 K (+1215°C / +2219°F) and receiving 818.50 S⊕ (~1,113,979 W/m²), TOI-3331 A b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-3331 A is classified as a stellar host with an effective photospheric temperature of 5,609 K, a radius of 0.952 R☉, a mass of 1.016 M☉, an estimated bolometric luminosity of 0.805 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.1 Gyr and a metallicity of [Fe/H] = 0.148 dex (metal-rich relative to the Sun). From Earth, TOI-3331 A shines at apparent V-band magnitude 11.635 (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-3331 A |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,609 K |
| Stellar Radius | 0.9520 R☉ |
| Stellar Mass | 1.0160 M☉ |
| Bolometric Luminosity | 0.805 L☉ |
| Metallicity [Fe/H] | 0.148 dex |
| Stellar Age | 2.100 Gyr |
| Apparent Magnitude | V: 11.635 · G: 11.831 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.031440 AU |
| Orbital Period | 2.018 days |
| Mean Orbital Velocity | 169.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 85.4000° |
| Mean Bulk Density | 1.82 g/cm³ (83.4 km/s vesc) |
| Insolation Flux | 818.5000 S⊕ (~1,113,979 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 708.400 LY (217.193 pc) |