TOI-5502 b
Astrophysical Synthesis & Habitability Characterization
TOI-5502 b is a confirmed sub-neptune exoplanet orbiting the star TOI-5502, located approximately 811 light-years (248.65 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 0.0818% across the stellar disk), this world measures 4.129 Earth radii (0.37 Jupiter radii) and has a measured mass of 15.9 Earth masses. Combining its mass and radius yields a mean bulk density of 1.25 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.93 g⊕ (9.12 m/s²), and an escape velocity of 22 km/s.
In its orbital architecture around TOI-5502, TOI-5502 b completes one full revolution every 11.626 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 870 K (+597°C / +1107°F) and receiving 95.20 S⊕ (~129,561 W/m²), TOI-5502 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5502 is classified as a stellar host with an effective photospheric temperature of 6,089 K, a radius of 1.3238 R☉, a mass of 1.244 M☉, an estimated bolometric luminosity of 2.161 L☉. From Earth, TOI-5502 shines at apparent V-band magnitude 10.881 (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-5502 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,089 K |
| Stellar Radius | 1.3238 R☉ |
| Stellar Mass | 1.2440 M☉ |
| Bolometric Luminosity | 2.161 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 10.881 · G: 10.704 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 11.626 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 88.9351° |
| Mean Bulk Density | 1.25 g/cm³ (22 km/s vesc) |
| Insolation Flux | 95.1955 S⊕ (~129,561 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 811.000 LY (248.654 pc) |