TOI-3664 b
Astrophysical Synthesis & Habitability Characterization
TOI-3664 b is a confirmed gas giant exoplanet orbiting the star TOI-3664, located approximately 1515.8 light-years (464.75 parsecs) from the Solar System. First announced in 2026 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 1.2798% across the stellar disk), this world measures 13.697 Earth radii (1.22 Jupiter radii) and has a measured mass of 114.418 Earth masses (0.36 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.25 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.61 g⊕ (5.98 m/s²), and an escape velocity of 32.3 km/s.
In its orbital architecture around TOI-3664, TOI-3664 b completes one full revolution every 3.297 Earth days at a semi-major axis of 0.0431 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 142.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.159 carries the world between 0.0362 AU at periapsis and 0.05 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1232 K (+959°C / +1758°F) and receiving 349.54 S⊕ (~475,729 W/m²), TOI-3664 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-3664 is classified as a stellar host with an effective photospheric temperature of 5,593 K, a radius of 1.11 R☉, a mass of 0.98 M☉, an estimated bolometric luminosity of 1.082 L☉. Stellar evolution modeling indicates an estimated stellar age of 9 Gyr and a metallicity of [Fe/H] = 0.17 dex (metal-rich relative to the Sun). From Earth, TOI-3664 shines at apparent V-band magnitude 13.883 (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-3664 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,593 K |
| Stellar Radius | 1.1100 R☉ |
| Stellar Mass | 0.9800 M☉ |
| Bolometric Luminosity | 1.082 L☉ |
| Metallicity [Fe/H] | 0.170 dex |
| Stellar Age | 9.000 Gyr |
| Apparent Magnitude | V: 13.883 · G: 13.546 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.043100 AU |
| Orbital Period | 3.297 days |
| Mean Orbital Velocity | 142.2 km/s |
| Orbital Eccentricity (e) | 0.15900 |
| Orbital Inclination (i) | 87.8000° |
| Mean Bulk Density | 0.25 g/cm³ (32.3 km/s vesc) |
| Insolation Flux | 349.5440 S⊕ (~475,729 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1515.800 LY (464.748 pc) |