TOI-519 b
Astrophysical Synthesis & Habitability Characterization
TOI-519 b is a confirmed gas giant exoplanet orbiting the star TOI-519, located approximately 376.9 light-years (115.56 parsecs) from the Solar System. First announced in 2021 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 9.1452% across the stellar disk), this world measures 11.545 Earth radii (1.03 Jupiter radii) and has a measured mass of 147.155 Earth masses (0.46 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.53 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 39.9 km/s.
In its orbital architecture around TOI-519, TOI-519 b completes one full revolution every 1.265 Earth days at a semi-major axis of 0.0159 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 136.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.33, swinging from 0.0107 AU at periapsis out to 0.0211 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 687 K (+414°C / +777°F) and receiving 54.00 S⊕ (~73,494 W/m²), TOI-519 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-519 is classified as a low-mass red dwarf of spectral type M V with an effective photospheric temperature of 3,322 K, a radius of 0.35 R☉, a mass of 0.335 M☉, an estimated bolometric luminosity of 0.013 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.4 Gyr and a metallicity of [Fe/H] = 0.27 dex (metal-rich relative to the Sun). From Earth, TOI-519 shines at apparent V-band magnitude 17.35 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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-519 |
| Spectral Type | M V |
| Effective Temp (Teff) | 3,322 K |
| Stellar Radius | 0.3500 R☉ |
| Stellar Mass | 0.3350 M☉ |
| Bolometric Luminosity | 0.013 L☉ |
| Metallicity [Fe/H] | 0.270 dex |
| Stellar Age | 5.400 Gyr |
| Apparent Magnitude | V: 17.350 · G: 15.707 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.015900 AU |
| Orbital Period | 1.265 days |
| Mean Orbital Velocity | 136.7 km/s |
| Orbital Eccentricity (e) | 0.33000 |
| Orbital Inclination (i) | 88.9000° |
| Mean Bulk Density | 0.53 g/cm³ (39.9 km/s vesc) |
| Insolation Flux | 54.0000 S⊕ (~73,494 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 376.900 LY (115.557 pc) |