TOI-1742 b
Astrophysical Synthesis & Habitability Characterization
TOI-1742 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1742, located approximately 237.7 light-years (72.89 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 0.0368% across the stellar disk), this world measures 2.365 Earth radii and has a measured mass of 9.7 Earth masses. Combining its mass and radius yields a mean bulk density of 4.04 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.73 g⊕ (16.97 m/s²), and an escape velocity of 22.7 km/s.
In its orbital architecture around TOI-1742, TOI-1742 b completes one full revolution every 21.269 Earth days at a semi-major axis of 0.154 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 78.8 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.3, swinging from 0.1078 AU at periapsis out to 0.2002 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 694 K (+421°C / +790°F) and receiving 58.62 S⊕ (~79,779 W/m²), TOI-1742 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1742 is classified as a stellar host with an effective photospheric temperature of 5,815 K, a radius of 1.131 R☉, a mass of 1.0861 M☉, an estimated bolometric luminosity of 1.312 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.9 Gyr and a metallicity of [Fe/H] = 0.193 dex (metal-rich relative to the Sun). From Earth, TOI-1742 shines at apparent V-band magnitude 8.863 (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-1742 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,815 K |
| Stellar Radius | 1.1310 R☉ |
| Stellar Mass | 1.0861 M☉ |
| Bolometric Luminosity | 1.312 L☉ |
| Metallicity [Fe/H] | 0.193 dex |
| Stellar Age | 3.900 Gyr |
| Apparent Magnitude | V: 8.863 · G: 8.728 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.154000 AU |
| Orbital Period | 21.269 days |
| Mean Orbital Velocity | 78.8 km/s |
| Orbital Eccentricity (e) | 0.30000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.04 g/cm³ (22.7 km/s vesc) |
| Insolation Flux | 58.6180 S⊕ (~79,779 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 237.700 LY (72.887 pc) |