TOI-2196 b
Astrophysical Synthesis & Habitability Characterization
TOI-2196 b is a confirmed sub-neptune exoplanet orbiting the star TOI-2196, located approximately 847.8 light-years (259.95 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 0.0952% across the stellar disk), this world measures 3.51 Earth radii (0.31 Jupiter radii) and has a measured mass of 26 Earth masses. Combining its mass and radius yields a mean bulk density of 3.32 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 2.11 g⊕ (20.69 m/s²), and an escape velocity of 30.4 km/s.
In its orbital architecture around TOI-2196, TOI-2196 b completes one full revolution every 1.195 Earth days at a semi-major axis of 0.02234 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 203.4 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 1860 K (+1587°C / +2889°F) and receiving 2,000.00 S⊕ (~2,722,000 W/m²), TOI-2196 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2196 is classified as a solar-type yellow star of spectral type G V with an effective photospheric temperature of 5,634 K, a radius of 1.043 R☉, a mass of 1.032 M☉, an estimated bolometric luminosity of 0.983 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.5 Gyr and a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, TOI-2196 shines at apparent V-band magnitude 12.297 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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-2196 |
| Spectral Type | G V |
| Effective Temp (Teff) | 5,634 K |
| Stellar Radius | 1.0430 R☉ |
| Stellar Mass | 1.0320 M☉ |
| Bolometric Luminosity | 0.983 L☉ |
| Metallicity [Fe/H] | 0.140 dex |
| Stellar Age | 4.500 Gyr |
| Apparent Magnitude | V: 12.297 · G: 11.826 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.022340 AU |
| Orbital Period | 1.195 days |
| Mean Orbital Velocity | 203.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 81.1100° |
| Mean Bulk Density | 3.32 g/cm³ (30.4 km/s vesc) |
| Insolation Flux | 2000.0000 S⊕ (~2,722,000 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 847.800 LY (259.947 pc) |