TOI-6649 b
Astrophysical Synthesis & Habitability Characterization
TOI-6649 b is a confirmed gas giant exoplanet orbiting the star TOI-6649, located approximately 656.3 light-years (201.21 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 0.8843% across the stellar disk), this world measures 14.011 Earth radii (1.25 Jupiter radii) and has a measured mass of 204.999 Earth masses (0.64 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.41 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.04 g⊕ (10.2 m/s²), and an escape velocity of 42.8 km/s.
In its orbital architecture around TOI-6649, TOI-6649 b completes one full revolution every 5.988 Earth days at a semi-major axis of 0.0697 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 126.6 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.039 (ranging from 0.067 AU at periapsis to 0.0724 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1345 K (+1072°C / +1962°F) and receiving 194.21 S⊕ (~264,324 W/m²), TOI-6649 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-6649 is classified as a stellar host with an effective photospheric temperature of 6,302 K, a radius of 1.366 R☉, a mass of 1.259 M☉, an estimated bolometric luminosity of 2.641 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.4 Gyr and a metallicity of [Fe/H] = 0.184 dex (metal-rich relative to the Sun). From Earth, TOI-6649 shines at apparent V-band magnitude 10.322 (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-6649 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,302 K |
| Stellar Radius | 1.3660 R☉ |
| Stellar Mass | 1.2590 M☉ |
| Bolometric Luminosity | 2.641 L☉ |
| Metallicity [Fe/H] | 0.184 dex |
| Stellar Age | 2.400 Gyr |
| Apparent Magnitude | V: 10.322 · G: 10.121 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.069700 AU |
| Orbital Period | 5.988 days |
| Mean Orbital Velocity | 126.6 km/s |
| Orbital Eccentricity (e) | 0.03900 |
| Orbital Inclination (i) | 84.6600° |
| Mean Bulk Density | 0.41 g/cm³ (42.8 km/s vesc) |
| Insolation Flux | 194.2130 S⊕ (~264,324 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 656.300 LY (201.210 pc) |