TOI-3819 b
Astrophysical Synthesis & Habitability Characterization
TOI-3819 b is a confirmed gas giant exoplanet orbiting the star TOI-3819, located approximately 1820.4 light-years (558.14 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 0.6132% across the stellar disk), this world measures 13.137 Earth radii (1.17 Jupiter radii) and has a measured mass of 352.79 Earth masses (1.11 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.86 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.04 g⊕ (20.01 m/s²), and an escape velocity of 58 km/s.
In its orbital architecture around TOI-3819, TOI-3819 b completes one full revolution every 3.244 Earth days at a semi-major axis of 0.04611 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 154.6 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 1633 K (+1360°C / +2480°F) and receiving 1,186.00 S⊕ (~1,614,146 W/m²), TOI-3819 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-3819 is classified as a stellar host with an effective photospheric temperature of 5,859 K, a radius of 1.538 R☉, a mass of 1.242 M☉, an estimated bolometric luminosity of 2.501 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.5 Gyr and a metallicity of [Fe/H] = 0.273 dex (metal-rich relative to the Sun). From Earth, TOI-3819 shines at apparent V-band magnitude 12.542 (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-3819 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,859 K |
| Stellar Radius | 1.5380 R☉ |
| Stellar Mass | 1.2420 M☉ |
| Bolometric Luminosity | 2.501 L☉ |
| Metallicity [Fe/H] | 0.273 dex |
| Stellar Age | 4.500 Gyr |
| Apparent Magnitude | V: 12.542 · G: 12.413 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.046110 AU |
| Orbital Period | 3.244 days |
| Mean Orbital Velocity | 154.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 82.7900° |
| Mean Bulk Density | 0.86 g/cm³ (58 km/s vesc) |
| Insolation Flux | 1186.0000 S⊕ (~1,614,146 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1820.400 LY (558.141 pc) |