TOI-532 b
Astrophysical Synthesis & Habitability Characterization
TOI-532 b is a confirmed sub-neptune exoplanet orbiting the star TOI-532, located approximately 440.5 light-years (135.05 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 0.7601% across the stellar disk), this world measures 5.82 Earth radii (0.52 Jupiter radii) and has a measured mass of 61.5 Earth masses (0.19 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.72 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.82 g⊕ (17.85 m/s²), and an escape velocity of 36.4 km/s.
In its orbital architecture around TOI-532, TOI-532 b completes one full revolution every 2.327 Earth days at a semi-major axis of 0.0296 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 138.4 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 867 K (+594°C / +1101°F) and receiving 94.10 S⊕ (~128,070 W/m²), TOI-532 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-532 is classified as a stellar host with an effective photospheric temperature of 3,927 K, a radius of 0.612 R☉, a mass of 0.639 M☉, an estimated bolometric luminosity of 0.08 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.1 Gyr and a metallicity of [Fe/H] = 0.338 dex (metal-rich relative to the Sun). From Earth, TOI-532 shines at apparent V-band magnitude 14.413 (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-532 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,927 K |
| Stellar Radius | 0.6120 R☉ |
| Stellar Mass | 0.6390 M☉ |
| Bolometric Luminosity | 0.08 L☉ |
| Metallicity [Fe/H] | 0.338 dex |
| Stellar Age | 7.100 Gyr |
| Apparent Magnitude | V: 14.413 · G: 13.665 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.029600 AU |
| Orbital Period | 2.327 days |
| Mean Orbital Velocity | 138.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.0800° |
| Mean Bulk Density | 1.72 g/cm³ (36.4 km/s vesc) |
| Insolation Flux | 94.1000 S⊕ (~128,070 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 440.500 LY (135.047 pc) |