TOI-4487 A b
Astrophysical Synthesis & Habitability Characterization
TOI-4487 A b is a confirmed gas giant exoplanet orbiting the star TOI-4487 A, located approximately 1562.8 light-years (479.15 parsecs) from the Solar System. First announced in 2025 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.6715% across the stellar disk), this world measures 14.605 Earth radii (1.3 Jupiter radii) and has a measured mass of 397.286 Earth masses (1.25 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.7 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.86 g⊕ (18.24 m/s²), and an escape velocity of 58.3 km/s.
In its orbital architecture around TOI-4487 A, TOI-4487 A b completes one full revolution every 3.954 Earth days at a semi-major axis of 0.05448 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 149.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.083 carries the world between 0.05 AU at periapsis and 0.059 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1639 K (+1366°C / +2491°F) and receiving 1,203.00 S⊕ (~1,637,283 W/m²), TOI-4487 A b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-4487 A is classified as a stellar host with an effective photospheric temperature of 6,206 K, a radius of 1.634 R☉, a mass of 1.378 M☉, an estimated bolometric luminosity of 3.553 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.45 Gyr and a metallicity of [Fe/H] = 0.216 dex (metal-rich relative to the Sun). From Earth, TOI-4487 A shines at apparent V-band magnitude 12.109 (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-4487 A |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,206 K |
| Stellar Radius | 1.6340 R☉ |
| Stellar Mass | 1.3780 M☉ |
| Bolometric Luminosity | 3.553 L☉ |
| Metallicity [Fe/H] | 0.216 dex |
| Stellar Age | 2.450 Gyr |
| Apparent Magnitude | V: 12.109 · G: 11.927 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.054480 AU |
| Orbital Period | 3.954 days |
| Mean Orbital Velocity | 149.9 km/s |
| Orbital Eccentricity (e) | 0.08300 |
| Orbital Inclination (i) | 86.8500° |
| Mean Bulk Density | 0.7 g/cm³ (58.3 km/s vesc) |
| Insolation Flux | 1203.0000 S⊕ (~1,637,283 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1562.800 LY (479.145 pc) |