TOI-1246 b
Astrophysical Synthesis & Habitability Characterization
TOI-1246 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1246, located approximately 552.6 light-years (169.42 parsecs) from the Solar System. First announced in 2022 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.103% across the stellar disk), this world measures 3.01 Earth radii (0.27 Jupiter radii) and has a measured mass of 8.1 Earth masses. Combining its mass and radius yields a mean bulk density of 1.64 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.89 g⊕ (8.73 m/s²), and an escape velocity of 18.3 km/s.
In its orbital architecture around TOI-1246, TOI-1246 b completes one full revolution every 4.307 Earth days at a semi-major axis of 0.049 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 123.8 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 955 K (+682°C / +1260°F) and receiving 196.00 S⊕ (~266,756 W/m²), TOI-1246 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1246 is classified as an orange K-type star of spectral type K V with an effective photospheric temperature of 5,151 K, a radius of 0.86 R☉, a mass of 0.87 M☉, an estimated bolometric luminosity of 0.467 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.3 Gyr and a metallicity of [Fe/H] = 0.17 dex (metal-rich relative to the Sun). From Earth, TOI-1246 shines at apparent V-band magnitude 11.632 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-1246 system is a multi-planet architecture hosting 4 confirmed worlds, with TOI-1246 b sharing its stellar neighborhood alongside TOI-1246 c, TOI-1246 d, TOI-1246 e.
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-1246 |
| Spectral Type | K V |
| Effective Temp (Teff) | 5,151 K |
| Stellar Radius | 0.8600 R☉ |
| Stellar Mass | 0.8700 M☉ |
| Bolometric Luminosity | 0.467 L☉ |
| Metallicity [Fe/H] | 0.170 dex |
| Stellar Age | 6.300 Gyr |
| Apparent Magnitude | V: 11.632 · G: 11.729 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.049000 AU |
| Orbital Period | 4.307 days |
| Mean Orbital Velocity | 123.8 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 87.9000° |
| Mean Bulk Density | 1.64 g/cm³ (18.3 km/s vesc) |
| Insolation Flux | 196.0000 S⊕ (~266,756 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 552.600 LY (169.422 pc) |