TOI-1272 b
Astrophysical Synthesis & Habitability Characterization
TOI-1272 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1272, located approximately 448.7 light-years (137.57 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 0.2383% across the stellar disk), this world measures 4.26 Earth radii (0.38 Jupiter radii) and has a measured mass of 24.1 Earth masses. Combining its mass and radius yields a mean bulk density of 1.72 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.33 g⊕ (13.04 m/s²), and an escape velocity of 26.6 km/s.
In its orbital architecture around TOI-1272, TOI-1272 b completes one full revolution every 3.316 Earth days at a semi-major axis of 0.041 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 134.5 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.345, swinging from 0.0269 AU at periapsis out to 0.0551 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1051 K (+778°C / +1432°F) and receiving 120.60 S⊕ (~164,130 W/m²), TOI-1272 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1272 is classified as an orange K-type star of spectral type K2 V - K3 V with an effective photospheric temperature of 4,985 K, a radius of 0.8 R☉, a mass of 0.828 M☉, an estimated bolometric luminosity of 0.355 L☉. Stellar evolution modeling indicates an estimated stellar age of 7 Gyr and a metallicity of [Fe/H] = 0.1 dex (metal-rich relative to the Sun). From Earth, TOI-1272 shines at apparent V-band magnitude 11.758 (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-1272 |
| Spectral Type | K2 V - K3 V |
| Effective Temp (Teff) | 4,985 K |
| Stellar Radius | 0.8000 R☉ |
| Stellar Mass | 0.8280 M☉ |
| Bolometric Luminosity | 0.355 L☉ |
| Metallicity [Fe/H] | 0.100 dex |
| Stellar Age | 7.000 Gyr |
| Apparent Magnitude | V: 11.758 · G: 11.600 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.041000 AU |
| Orbital Period | 3.316 days |
| Mean Orbital Velocity | 134.5 km/s |
| Orbital Eccentricity (e) | 0.34500 |
| Orbital Inclination (i) | 86.0000° |
| Mean Bulk Density | 1.72 g/cm³ (26.6 km/s vesc) |
| Insolation Flux | 120.5950 S⊕ (~164,130 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 448.700 LY (137.572 pc) |