TOI-3568 b
Astrophysical Synthesis & Habitability Characterization
TOI-3568 b is a confirmed sub-neptune exoplanet orbiting the star TOI-3568, located approximately 645.5 light-years (197.91 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.4567% across the stellar disk), this world measures 5.3 Earth radii (0.47 Jupiter radii) and has a measured mass of 26.4 Earth masses. Combining its mass and radius yields a mean bulk density of 0.98 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.94 g⊕ (9.22 m/s²), and an escape velocity of 25 km/s.
In its orbital architecture around TOI-3568, TOI-3568 b completes one full revolution every 4.418 Earth days at a semi-major axis of 0.0485 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 119.4 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.035 (ranging from 0.0468 AU at periapsis to 0.0502 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 899 K (+626°C / +1159°F) and receiving 130.15 S⊕ (~177,132 W/m²), TOI-3568 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-3568 is classified as a stellar host with an effective photospheric temperature of 4,969 K, a radius of 0.719 R☉, a mass of 0.78 M☉, an estimated bolometric luminosity of 0.283 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.1 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, TOI-3568 shines at apparent V-band magnitude 12.879 (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-3568 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,969 K |
| Stellar Radius | 0.7190 R☉ |
| Stellar Mass | 0.7800 M☉ |
| Bolometric Luminosity | 0.283 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | 6.100 Gyr |
| Apparent Magnitude | V: 12.879 · G: 12.700 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.048500 AU |
| Orbital Period | 4.418 days |
| Mean Orbital Velocity | 119.4 km/s |
| Orbital Eccentricity (e) | 0.03500 |
| Orbital Inclination (i) | 89.2000° |
| Mean Bulk Density | 0.98 g/cm³ (25 km/s vesc) |
| Insolation Flux | 130.1481 S⊕ (~177,132 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 645.500 LY (197.906 pc) |