TOI-2133 b
Astrophysical Synthesis & Habitability Characterization
TOI-2133 b is a confirmed sub-neptune exoplanet orbiting the star TOI-2133, located approximately 245.3 light-years (75.2 parsecs) from the Solar System. First announced in 2026 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.1228% across the stellar disk), this world measures 2.37 Earth radii and has a measured mass of 6.21 Earth masses. Combining its mass and radius yields a mean bulk density of 2.57 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.11 g⊕ (10.89 m/s²), and an escape velocity of 18.1 km/s.
In its orbital architecture around TOI-2133, TOI-2133 b completes one full revolution every 3.827 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 116.6 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 798 K (+525°C / +977°F) and receiving 81.11 S⊕ (~110,387 W/m²), TOI-2133 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2133 is classified as a stellar host with an effective photospheric temperature of 4,250 K, a radius of 0.62 R☉, a mass of 0.644 M☉, an estimated bolometric luminosity of 0.113 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, TOI-2133 shines at apparent V-band magnitude 12.008 (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-2133 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,250 K |
| Stellar Radius | 0.6200 R☉ |
| Stellar Mass | 0.6440 M☉ |
| Bolometric Luminosity | 0.113 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 12.008 · G: 11.632 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.041000 AU |
| Orbital Period | 3.827 days |
| Mean Orbital Velocity | 116.6 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.5000° |
| Mean Bulk Density | 2.57 g/cm³ (18.1 km/s vesc) |
| Insolation Flux | 81.1072 S⊕ (~110,387 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 245.300 LY (75.197 pc) |