TOI-4443 c
Astrophysical Synthesis & Habitability Characterization
TOI-4443 c is a confirmed sub-neptune exoplanet orbiting the star TOI-4443, located approximately 182.9 light-years (56.07 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 0.04% across the stellar disk), this world measures 2.22 Earth radii and has a measured mass of 5.56 Earth masses. Combining its mass and radius yields a mean bulk density of 2.8 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.13 g⊕ (11.08 m/s²), and an escape velocity of 17.7 km/s.
In its orbital architecture around TOI-4443, TOI-4443 c completes one full revolution every 10.309 Earth days. 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 846 K (+573°C / +1063°F) and receiving 120.87 S⊕ (~164,503 W/m²), TOI-4443 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4443 is classified as a stellar host with an effective photospheric temperature of 5,834 K, a radius of 1.0173 R☉, a mass of 1.05 M☉, an estimated bolometric luminosity of 1.076 L☉. From Earth, TOI-4443 shines at apparent V-band magnitude 8.493 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The TOI-4443 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-4443 c sharing its stellar neighborhood alongside TOI-4443.01.
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-4443 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,834 K |
| Stellar Radius | 1.0173 R☉ |
| Stellar Mass | 1.0500 M☉ |
| Bolometric Luminosity | 1.076 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 8.493 · G: 8.336 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 10.309 days |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.8 g/cm³ (17.7 km/s vesc) |
| Insolation Flux | 120.8695 S⊕ (~164,503 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 182.900 LY (56.074 pc) |