TOI-640 b
Astrophysical Synthesis & Habitability Characterization
TOI-640 b is a confirmed gas giant exoplanet orbiting the star TOI-640, located approximately 1115.4 light-years (342 parsecs) from the Solar System. First announced in 2021 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.7207% across the stellar disk), this world measures 19.279 Earth radii (1.72 Jupiter radii) and has a measured mass of 181.162 Earth masses (0.57 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.14 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.49 g⊕ (4.81 m/s²), and an escape velocity of 34.3 km/s.
In its orbital architecture around TOI-640, TOI-640 b completes one full revolution every 5.004 Earth days at a semi-major axis of 0.06608 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 143.7 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.013 (ranging from 0.0652 AU at periapsis to 0.0669 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1816 K (+1543°C / +2809°F) and receiving 1,150.12 S⊕ (~1,565,313 W/m²), TOI-640 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-640 is classified as a stellar host with an effective photospheric temperature of 6,460 K, a radius of 2.082 R☉, a mass of 1.536 M☉, an estimated bolometric luminosity of 6.773 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.99 Gyr and a metallicity of [Fe/H] = 0.072 dex (metal-rich relative to the Sun). From Earth, TOI-640 shines at apparent V-band magnitude 10.51 (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-640 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,460 K |
| Stellar Radius | 2.0820 R☉ |
| Stellar Mass | 1.5360 M☉ |
| Bolometric Luminosity | 6.773 L☉ |
| Metallicity [Fe/H] | 0.072 dex |
| Stellar Age | 1.990 Gyr |
| Apparent Magnitude | V: 10.510 · G: 10.401 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.066080 AU |
| Orbital Period | 5.004 days |
| Mean Orbital Velocity | 143.7 km/s |
| Orbital Eccentricity (e) | 0.01300 |
| Orbital Inclination (i) | 81.7900° |
| Mean Bulk Density | 0.14 g/cm³ (34.3 km/s vesc) |
| Insolation Flux | 1150.1200 S⊕ (~1,565,313 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1115.400 LY (341.997 pc) |