TOI-2443 b
Astrophysical Synthesis & Habitability Characterization
TOI-2443 b is a confirmed sub-neptune exoplanet orbiting the star TOI-2443, located approximately 78 light-years (23.93 parsecs) from the Solar System. First announced in 2023 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.1179% across the stellar disk), this world measures 2.363 Earth radii and has a measured mass of 4.8 Earth masses. Combining its mass and radius yields a mean bulk density of 2.01 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 0.86 g⊕ (8.43 m/s²), and an escape velocity of 15.9 km/s.
In its orbital architecture around TOI-2443, TOI-2443 b completes one full revolution every 15.669 Earth days at a semi-major axis of 0.105 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 72.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.301, swinging from 0.0734 AU at periapsis out to 0.1366 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 519 K (+246°C / +475°F) and receiving 13.29 S⊕ (~18,092 W/m²), TOI-2443 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-2443 is classified as an orange K-type star of spectral type K5 V with an effective photospheric temperature of 4,375 K, a radius of 0.631 R☉, a mass of 0.642 M☉, an estimated bolometric luminosity of 0.131 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.5 Gyr and a metallicity of [Fe/H] = -0.29 dex (metal-poor relative to the Sun). From Earth, TOI-2443 shines at apparent V-band magnitude 9.51 (accessible to binoculars and small amateur telescopes) 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-2443 |
| Spectral Type | K5 V |
| Effective Temp (Teff) | 4,375 K |
| Stellar Radius | 0.6310 R☉ |
| Stellar Mass | 0.6420 M☉ |
| Bolometric Luminosity | 0.131 L☉ |
| Metallicity [Fe/H] | -0.290 dex |
| Stellar Age | 7.500 Gyr |
| Apparent Magnitude | V: 9.510 · G: 9.033 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.105000 AU |
| Orbital Period | 15.669 days |
| Mean Orbital Velocity | 72.9 km/s |
| Orbital Eccentricity (e) | 0.30100 |
| Orbital Inclination (i) | 89.7200° |
| Mean Bulk Density | 2.01 g/cm³ (15.9 km/s vesc) |
| Insolation Flux | 13.2931 S⊕ (~18,092 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 78.000 LY (23.926 pc) |