TOI-5938 b

Astrophysical Synthesis & Habitability Characterization

TOI-5938 b is a confirmed sub-neptune exoplanet orbiting the star TOI-5938, located approximately 371.9 light-years (114.04 parsecs) from the Solar System. First announced in 2026 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.2419% across the stellar disk), this world measures 3.82 Earth radii (0.34 Jupiter radii) and has a measured mass of 14 Earth masses. Combining its mass and radius yields a mean bulk density of 1.38 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.96 g⊕ (9.41 m/s²), and an escape velocity of 21.4 km/s.

In its orbital architecture around TOI-5938, TOI-5938 b completes one full revolution every 2.26 Earth days at a semi-major axis of 0.0308 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 148.2 km/s (compared to Earth's 29.8 km/s).

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1077 K (+804°C / +1479°F) and receiving 249.27 S⊕ (~339,261 W/m²), TOI-5938 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star TOI-5938 is classified as a stellar host with an effective photospheric temperature of 4,650 K, a radius of 0.712 R☉, a mass of 0.744 M☉, an estimated bolometric luminosity of 0.213 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.07 dex (metal-rich relative to the Sun). From Earth, TOI-5938 shines at apparent V-band magnitude 12.31 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

Discovery Facility: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).