TOI-1758 b
Astrophysical Synthesis & Habitability Characterization
TOI-1758 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1758, located approximately 315.1 light-years (96.62 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.1679% across the stellar disk), this world measures 3.62 Earth radii (0.32 Jupiter radii) and has a measured mass of 6.9 Earth masses. Combining its mass and radius yields a mean bulk density of 0.8 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.53 g⊕ (5.2 m/s²), and an escape velocity of 15.4 km/s.
In its orbital architecture around TOI-1758, TOI-1758 b completes one full revolution every 20.705 Earth days at a semi-major axis of 0.141409 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 74.3 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 551 K (+278°C / +532°F) and receiving 21.05 S⊕ (~28,649 W/m²), TOI-1758 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1758 is classified as a stellar host with an effective photospheric temperature of 5,169 K, a radius of 0.81 R☉, a mass of 0.88 M☉, an estimated bolometric luminosity of 0.42 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.5 Gyr and a metallicity of [Fe/H] = -0.02 dex (near-solar heavy-element abundance). From Earth, TOI-1758 shines at apparent V-band magnitude 10.794 (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-1758 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,169 K |
| Stellar Radius | 0.8100 R☉ |
| Stellar Mass | 0.8800 M☉ |
| Bolometric Luminosity | 0.42 L☉ |
| Metallicity [Fe/H] | -0.020 dex |
| Stellar Age | 7.500 Gyr |
| Apparent Magnitude | V: 10.794 · G: 10.625 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.141409 AU |
| Orbital Period | 20.705 days |
| Mean Orbital Velocity | 74.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.8 g/cm³ (15.4 km/s vesc) |
| Insolation Flux | 21.0500 S⊕ (~28,649 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 315.100 LY (96.622 pc) |