TOI-6223 b
Astrophysical Synthesis & Habitability Characterization
TOI-6223 b is a confirmed sub-neptune exoplanet orbiting the star TOI-6223, located approximately 434.2 light-years (133.12 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 0.6512% across the stellar disk), this world measures 5.07 Earth radii (0.45 Jupiter radii) and has a measured mass of 22.6 Earth masses. Combining its mass and radius yields a mean bulk density of 0.96 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.88 g⊕ (8.63 m/s²), and an escape velocity of 23.6 km/s.
In its orbital architecture around TOI-6223, TOI-6223 b completes one full revolution every 3.855 Earth days at a semi-major axis of 0.04018 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 113.4 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 714 K (+441°C / +826°F) and receiving 41.86 S⊕ (~56,978 W/m²), TOI-6223 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-6223 is classified as a low-mass red dwarf of spectral type M0 V with an effective photospheric temperature of 3,895 K, a radius of 0.576 R☉, a mass of 0.582 M☉, an estimated bolometric luminosity of 0.069 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.8 Gyr and a metallicity of [Fe/H] = -0.12 dex (metal-poor relative to the Sun). From Earth, TOI-6223 shines at apparent V-band magnitude 14.22 (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-6223 |
| Spectral Type | M0 V |
| Effective Temp (Teff) | 3,895 K |
| Stellar Radius | 0.5760 R☉ |
| Stellar Mass | 0.5820 M☉ |
| Bolometric Luminosity | 0.069 L☉ |
| Metallicity [Fe/H] | -0.120 dex |
| Stellar Age | 9.800 Gyr |
| Apparent Magnitude | V: 14.220 · G: 13.620 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.040180 AU |
| Orbital Period | 3.855 days |
| Mean Orbital Velocity | 113.4 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 88.6800° |
| Mean Bulk Density | 0.96 g/cm³ (23.6 km/s vesc) |
| Insolation Flux | 41.8646 S⊕ (~56,978 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 434.200 LY (133.122 pc) |