TOI-5803 b
Astrophysical Synthesis & Habitability Characterization
TOI-5803 b is a confirmed sub-neptune exoplanet orbiting the star TOI-5803, located approximately 274 light-years (84.01 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 0.1549% across the stellar disk), this world measures 3.273 Earth radii (0.29 Jupiter radii) and has a measured mass of 10.7 Earth masses. Combining its mass and radius yields a mean bulk density of 1.68 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1 g⊕ (9.81 m/s²), and an escape velocity of 20.2 km/s.
In its orbital architecture around TOI-5803, TOI-5803 b completes one full revolution every 5.383 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 679 K (+406°C / +763°F) and receiving 73.72 S⊕ (~100,336 W/m²), TOI-5803 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5803 is classified as a stellar host with an effective photospheric temperature of 5,134 K, a radius of 0.7625 R☉, a mass of 0.87 M☉, an estimated bolometric luminosity of 0.362 L☉. From Earth, TOI-5803 shines at apparent V-band magnitude 10.655 (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-5803 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,134 K |
| Stellar Radius | 0.7625 R☉ |
| Stellar Mass | 0.8700 M☉ |
| Bolometric Luminosity | 0.362 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 10.655 · G: 10.478 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 5.383 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.3000° |
| Mean Bulk Density | 1.68 g/cm³ (20.2 km/s vesc) |
| Insolation Flux | 73.7220 S⊕ (~100,336 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 274.000 LY (84.013 pc) |