TOI-4773 b
Astrophysical Synthesis & Habitability Characterization
TOI-4773 b is a confirmed gas giant exoplanet orbiting the star TOI-4773, located approximately 1607.6 light-years (492.89 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 0.8106% across the stellar disk), this world measures 15.222 Earth radii (1.36 Jupiter radii) and has a measured mass of 1687.669 Earth masses (5.31 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.64 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 7.28 g⊕ (71.39 m/s²), and an escape velocity of 117.8 km/s.
In its orbital architecture around TOI-4773, TOI-4773 b completes one full revolution every 1.745 Earth days at a semi-major axis of 0.03216 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 200.5 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.024 (ranging from 0.0314 AU at periapsis to 0.0329 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 2255 K (+1982°C / +3600°F) and receiving 3,879.81 S⊕ (~5,280,417 W/m²), TOI-4773 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4773 is classified as a stellar host with an effective photospheric temperature of 6,740 K, a radius of 1.55 R☉, a mass of 1.452 M☉, an estimated bolometric luminosity of 4.448 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.07 Gyr and a metallicity of [Fe/H] = 0.11 dex (metal-rich relative to the Sun). From Earth, TOI-4773 shines at apparent V-band magnitude 12.075 (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-4773 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,740 K |
| Stellar Radius | 1.5500 R☉ |
| Stellar Mass | 1.4520 M☉ |
| Bolometric Luminosity | 4.448 L☉ |
| Metallicity [Fe/H] | 0.110 dex |
| Stellar Age | 1.070 Gyr |
| Apparent Magnitude | V: 12.075 · G: 11.719 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.032160 AU |
| Orbital Period | 1.745 days |
| Mean Orbital Velocity | 200.5 km/s |
| Orbital Eccentricity (e) | 0.02400 |
| Orbital Inclination (i) | 78.6400° |
| Mean Bulk Density | 2.64 g/cm³ (117.8 km/s vesc) |
| Insolation Flux | 3879.8071 S⊕ (~5,280,417 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1607.600 LY (492.888 pc) |