TOI-938 b
Astrophysical Synthesis & Habitability Characterization
TOI-938 b is a confirmed sub-neptune exoplanet orbiting the star TOI-938, located approximately 701.3 light-years (215.03 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 0.2016% across the stellar disk), this world measures 4.824 Earth radii (0.43 Jupiter radii) and has a measured mass of 20.8 Earth masses. Combining its mass and radius yields a mean bulk density of 1.02 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.89 g⊕ (8.73 m/s²), and an escape velocity of 23.2 km/s.
In its orbital architecture around TOI-938, TOI-938 b completes one full revolution every 8.807 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1073 K (+800°C / +1472°F) and receiving 220.74 S⊕ (~300,420 W/m²), TOI-938 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-938 is classified as a stellar host with an effective photospheric temperature of 5,829 K, a radius of 0.9851 R☉, a mass of 1.1 M☉, an estimated bolometric luminosity of 1.005 L☉. From Earth, TOI-938 shines at apparent V-band magnitude 11.389 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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-938 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,829 K |
| Stellar Radius | 0.9851 R☉ |
| Stellar Mass | 1.1000 M☉ |
| Bolometric Luminosity | 1.005 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 11.389 · G: 11.259 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 8.807 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 88.7833° |
| Mean Bulk Density | 1.02 g/cm³ (23.2 km/s vesc) |
| Insolation Flux | 220.7350 S⊕ (~300,420 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 701.300 LY (215.034 pc) |