TOI-4791 b
Astrophysical Synthesis & Habitability Characterization
TOI-4791 b is a confirmed gas giant exoplanet orbiting the star TOI-4791, located approximately 1072.4 light-years (328.8 parsecs) from the Solar System. First announced in 2023 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.6554% across the stellar disk), this world measures 12.442 Earth radii (1.11 Jupiter radii) and has a measured mass of 734.184 Earth masses (2.31 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.1 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 4.74 g⊕ (46.48 m/s²), and an escape velocity of 85.9 km/s.
In its orbital architecture around TOI-4791, TOI-4791 b completes one full revolution every 4.281 Earth days at a semi-major axis of 0.0555 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 141 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 1472 K (+1199°C / +2190°F) and receiving 783.20 S⊕ (~1,065,935 W/m²), TOI-4791 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4791 is classified as a stellar host with an effective photospheric temperature of 6,058 K, a radius of 1.409 R☉, a mass of 1.242 M☉, an estimated bolometric luminosity of 2.399 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.3 Gyr and a metallicity of [Fe/H] = 0.207 dex (metal-rich relative to the Sun). From Earth, TOI-4791 shines at apparent V-band magnitude 11.541 (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-4791 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,058 K |
| Stellar Radius | 1.4090 R☉ |
| Stellar Mass | 1.2420 M☉ |
| Bolometric Luminosity | 2.399 L☉ |
| Metallicity [Fe/H] | 0.207 dex |
| Stellar Age | 3.300 Gyr |
| Apparent Magnitude | V: 11.541 · G: 11.315 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.055500 AU |
| Orbital Period | 4.281 days |
| Mean Orbital Velocity | 141 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 85.5500° |
| Mean Bulk Density | 2.1 g/cm³ (85.9 km/s vesc) |
| Insolation Flux | 783.2000 S⊕ (~1,065,935 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1072.400 LY (328.802 pc) |