TOI-2031 A b
Astrophysical Synthesis & Habitability Characterization
TOI-2031 A b is a confirmed gas giant exoplanet orbiting the star TOI-2031 A, located approximately 900.5 light-years (276.11 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 1.1008% across the stellar disk), this world measures 14.202 Earth radii (1.27 Jupiter radii) and has a measured mass of 254.263 Earth masses (0.8 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.49 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.26 g⊕ (12.36 m/s²), and an escape velocity of 47.3 km/s.
In its orbital architecture around TOI-2031 A, TOI-2031 A b completes one full revolution every 5.715 Earth days at a semi-major axis of 0.066 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 125.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.076 carries the world between 0.061 AU at periapsis and 0.071 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1358 K (+1085°C / +1985°F) and receiving 567.00 S⊕ (~771,687 W/m²), TOI-2031 A b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2031 A is classified as a stellar host with an effective photospheric temperature of 6,490 K, a radius of 1.241 R☉, a mass of 1.174 M☉, an estimated bolometric luminosity of 2.451 L☉. Stellar evolution modeling indicates an estimated stellar age of 2 Gyr and a metallicity of [Fe/H] = -0.24 dex (metal-poor relative to the Sun). From Earth, TOI-2031 A shines at apparent V-band magnitude 11.254 (faint and requiring research-grade or CCD telescopic photometry) in the Northern 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-2031 A |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,490 K |
| Stellar Radius | 1.2410 R☉ |
| Stellar Mass | 1.1740 M☉ |
| Bolometric Luminosity | 2.451 L☉ |
| Metallicity [Fe/H] | -0.240 dex |
| Stellar Age | 2.000 Gyr |
| Apparent Magnitude | V: 11.254 · G: 11.114 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.066000 AU |
| Orbital Period | 5.715 days |
| Mean Orbital Velocity | 125.6 km/s |
| Orbital Eccentricity (e) | 0.07600 |
| Orbital Inclination (i) | 88.3200° |
| Mean Bulk Density | 0.49 g/cm³ (47.3 km/s vesc) |
| Insolation Flux | 567.0000 S⊕ (~771,687 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 900.500 LY (276.105 pc) |