TOI-1751 b
Astrophysical Synthesis & Habitability Characterization
TOI-1751 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1751, located approximately 369.6 light-years (113.34 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 0.0424% across the stellar disk), this world measures 2.951 Earth radii and has a measured mass of 19.5 Earth masses. Combining its mass and radius yields a mean bulk density of 4.18 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 2.24 g⊕ (21.97 m/s²), and an escape velocity of 28.8 km/s.
In its orbital architecture around TOI-1751, TOI-1751 b completes one full revolution every 37.469 Earth days at a semi-major axis of 0.215 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 62.4 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.327, swinging from 0.1447 AU at periapsis out to 0.2853 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 652 K (+379°C / +714°F) and receiving 192.52 S⊕ (~262,021 W/m²), TOI-1751 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1751 is classified as a stellar host with an effective photospheric temperature of 5,970 K, a radius of 1.3137 R☉, a mass of 0.9382 M☉, an estimated bolometric luminosity of 1.967 L☉. Stellar evolution modeling indicates an estimated stellar age of 9 Gyr and a metallicity of [Fe/H] = -0.373 dex (metal-poor relative to the Sun). From Earth, TOI-1751 shines at apparent V-band magnitude 9.327 (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-1751 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,970 K |
| Stellar Radius | 1.3137 R☉ |
| Stellar Mass | 0.9382 M☉ |
| Bolometric Luminosity | 1.967 L☉ |
| Metallicity [Fe/H] | -0.373 dex |
| Stellar Age | 9.000 Gyr |
| Apparent Magnitude | V: 9.327 · G: 9.189 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.215000 AU |
| Orbital Period | 37.469 days |
| Mean Orbital Velocity | 62.4 km/s |
| Orbital Eccentricity (e) | 0.32700 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.18 g/cm³ (28.8 km/s vesc) |
| Insolation Flux | 192.5210 S⊕ (~262,021 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 369.600 LY (113.335 pc) |