TOI-4515 b
Astrophysical Synthesis & Habitability Characterization
TOI-4515 b is a confirmed gas giant exoplanet orbiting the star TOI-4515, located approximately 631.1 light-years (193.5 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 1.6832% across the stellar disk), this world measures 12.17 Earth radii (1.09 Jupiter radii) and has a measured mass of 637 Earth masses (2 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.95 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 4.3 g⊕ (42.17 m/s²), and an escape velocity of 80.9 km/s.
In its orbital architecture around TOI-4515, TOI-4515 b completes one full revolution every 15.266 Earth days at a semi-major axis of 0.118 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 84.1 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.461, swinging from 0.0636 AU at periapsis out to 0.1724 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 705 K (+432°C / +810°F) and receiving 42.30 S⊕ (~57,569 W/m²), TOI-4515 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4515 is classified as a solar-type yellow star of spectral type G8/G9 with an effective photospheric temperature of 5,433 K, a radius of 0.86 R☉, a mass of 0.949 M☉, an estimated bolometric luminosity of 0.578 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.2 Gyr and a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, TOI-4515 shines at apparent V-band magnitude 11.938 (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-4515 |
| Spectral Type | G8/G9 |
| Effective Temp (Teff) | 5,433 K |
| Stellar Radius | 0.8600 R☉ |
| Stellar Mass | 0.9490 M☉ |
| Bolometric Luminosity | 0.578 L☉ |
| Metallicity [Fe/H] | 0.050 dex |
| Stellar Age | 1.200 Gyr |
| Apparent Magnitude | V: 11.938 · G: 11.812 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.118000 AU |
| Orbital Period | 15.266 days |
| Mean Orbital Velocity | 84.1 km/s |
| Orbital Eccentricity (e) | 0.46100 |
| Orbital Inclination (i) | 87.9540° |
| Mean Bulk Density | 1.95 g/cm³ (80.9 km/s vesc) |
| Insolation Flux | 42.2987 S⊕ (~57,569 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 631.100 LY (193.499 pc) |