TOI-1249 b
Astrophysical Synthesis & Habitability Characterization
TOI-1249 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1249, located approximately 455 light-years (139.49 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 0.0939% across the stellar disk), this world measures 3.271 Earth radii (0.29 Jupiter radii) and has a measured mass of 11.9 Earth masses. Combining its mass and radius yields a mean bulk density of 1.87 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.11 g⊕ (10.89 m/s²), and an escape velocity of 21.3 km/s.
In its orbital architecture around TOI-1249, TOI-1249 b completes one full revolution every 13.079 Earth days at a semi-major axis of 0.109 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 90.7 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 727 K (+454°C / +849°F) and receiving 48.61 S⊕ (~66,152 W/m²), TOI-1249 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1249 is classified as a stellar host with an effective photospheric temperature of 5,497 K, a radius of 0.9785 R☉, a mass of 1.0062 M☉, an estimated bolometric luminosity of 0.784 L☉. Stellar evolution modeling indicates an estimated stellar age of 4 Gyr and a metallicity of [Fe/H] = 0.297 dex (metal-rich relative to the Sun). From Earth, TOI-1249 shines at apparent V-band magnitude 11.089 (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-1249 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,497 K |
| Stellar Radius | 0.9785 R☉ |
| Stellar Mass | 1.0062 M☉ |
| Bolometric Luminosity | 0.784 L☉ |
| Metallicity [Fe/H] | 0.297 dex |
| Stellar Age | 4.000 Gyr |
| Apparent Magnitude | V: 11.089 · G: 10.699 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.109000 AU |
| Orbital Period | 13.079 days |
| Mean Orbital Velocity | 90.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.87 g/cm³ (21.3 km/s vesc) |
| Insolation Flux | 48.6058 S⊕ (~66,152 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 455.000 LY (139.490 pc) |