TOI-5319 b
Astrophysical Synthesis & Habitability Characterization
TOI-5319 b is a confirmed sub-neptune exoplanet orbiting the star TOI-5319, located approximately 199.5 light-years (61.17 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.2862% across the stellar disk), this world measures 2.83 Earth radii and has a measured mass of 8.4 Earth masses. Combining its mass and radius yields a mean bulk density of 2.04 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.05 g⊕ (10.3 m/s²), and an escape velocity of 19.3 km/s.
In its orbital architecture around TOI-5319, TOI-5319 b completes one full revolution every 4.079 Earth days at a semi-major axis of 0.0506 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 135 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 695 K (+422°C / +792°F) and receiving 38.79 S⊕ (~52,791 W/m²), TOI-5319 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5319 is classified as a low-mass red dwarf of spectral type M with an effective photospheric temperature of 3,580 K, a radius of 0.485 R☉, a mass of 0.5 M☉, an estimated bolometric luminosity of 0.035 L☉. From Earth, TOI-5319 shines at apparent V-band magnitude 13.947 (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-5319 |
| Spectral Type | M |
| Effective Temp (Teff) | 3,580 K |
| Stellar Radius | 0.4850 R☉ |
| Stellar Mass | 0.5000 M☉ |
| Bolometric Luminosity | 0.035 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 13.947 · G: 13.134 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.050600 AU |
| Orbital Period | 4.079 days |
| Mean Orbital Velocity | 135 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.2500° |
| Mean Bulk Density | 2.04 g/cm³ (19.3 km/s vesc) |
| Insolation Flux | 38.7885 S⊕ (~52,791 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 199.500 LY (61.171 pc) |