TOI-3523 A b
Astrophysical Synthesis & Habitability Characterization
TOI-3523 A b is a confirmed gas giant exoplanet orbiting the star TOI-3523 A, located approximately 2104.7 light-years (645.29 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 1.0228% across the stellar disk), this world measures 15.973 Earth radii (1.43 Jupiter radii) and has a measured mass of 435.425 Earth masses (1.37 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.59 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.71 g⊕ (16.77 m/s²), and an escape velocity of 58.4 km/s.
In its orbital architecture around TOI-3523 A, TOI-3523 A b completes one full revolution every 2.305 Earth days at a semi-major axis of 0.03559 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 168 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.047 (ranging from 0.0339 AU at periapsis to 0.0373 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1984 K (+1711°C / +3112°F) and receiving 2,590.00 S⊕ (~3,524,990 W/m²), TOI-3523 A b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-3523 A is classified as a stellar host with an effective photospheric temperature of 6,450 K, a radius of 1.448 R☉, a mass of 1.131 M☉, an estimated bolometric luminosity of 3.256 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.3 Gyr and a metallicity of [Fe/H] = -0.366 dex (metal-poor relative to the Sun). From Earth, TOI-3523 A shines at apparent V-band magnitude 12.56 (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-3523 A |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,450 K |
| Stellar Radius | 1.4480 R☉ |
| Stellar Mass | 1.1310 M☉ |
| Bolometric Luminosity | 3.256 L☉ |
| Metallicity [Fe/H] | -0.366 dex |
| Stellar Age | 4.300 Gyr |
| Apparent Magnitude | V: 12.560 · G: 12.495 |
| System Architecture | 3 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.035590 AU |
| Orbital Period | 2.305 days |
| Mean Orbital Velocity | 168 km/s |
| Orbital Eccentricity (e) | 0.04700 |
| Orbital Inclination (i) | 88.3000° |
| Mean Bulk Density | 0.59 g/cm³ (58.4 km/s vesc) |
| Insolation Flux | 2590.0000 S⊕ (~3,524,990 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2104.700 LY (645.294 pc) |