TOI-1718 b
Astrophysical Synthesis & Habitability Characterization
TOI-1718 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1718, located approximately 170.6 light-years (52.3 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 0.1608% across the stellar disk), this world measures 4.108 Earth radii (0.37 Jupiter radii) and has a measured mass of 15.8 Earth masses. Combining its mass and radius yields a mean bulk density of 1.26 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.94 g⊕ (9.22 m/s²), and an escape velocity of 21.9 km/s.
In its orbital architecture around TOI-1718, TOI-1718 b completes one full revolution every 5.587 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 948 K (+675°C / +1247°F) and receiving 134.16 S⊕ (~182,585 W/m²), TOI-1718 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1718 is classified as a stellar host with an effective photospheric temperature of 5,305 K, a radius of 0.9393 R☉, a mass of 0.93 M☉, an estimated bolometric luminosity of 0.627 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.2 dex (metal-rich relative to the Sun). From Earth, TOI-1718 shines at apparent V-band magnitude 8.96 (accessible to binoculars and small amateur telescopes) 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-1718 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,305 K |
| Stellar Radius | 0.9393 R☉ |
| Stellar Mass | 0.9300 M☉ |
| Bolometric Luminosity | 0.627 L☉ |
| Metallicity [Fe/H] | 0.200 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 8.960 · G: 8.755 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 5.587 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 87.8830° |
| Mean Bulk Density | 1.26 g/cm³ (21.9 km/s vesc) |
| Insolation Flux | 134.1550 S⊕ (~182,585 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 170.600 LY (52.304 pc) |