TOI-5739 b
Astrophysical Synthesis & Habitability Characterization
TOI-5739 b is a confirmed sub-neptune exoplanet orbiting the star TOI-5739, located approximately 201.8 light-years (61.87 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 0.0205% across the stellar disk), this world measures 2.33 Earth radii and has a measured mass of 6.04 Earth masses. Combining its mass and radius yields a mean bulk density of 2.63 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.11 g⊕ (10.89 m/s²), and an escape velocity of 18 km/s.
In its orbital architecture around TOI-5739, TOI-5739 b completes one full revolution every 8.431 Earth days. 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 1128 K (+855°C / +1571°F) and receiving 383.11 S⊕ (~521,413 W/m²), TOI-5739 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-5739 is classified as a stellar host with an effective photospheric temperature of 6,104 K, a radius of 1.4914 R☉, a mass of 1.15 M☉, an estimated bolometric luminosity of 2.77 L☉. From Earth, TOI-5739 shines at apparent V-band magnitude 7.65 (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-5739 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,104 K |
| Stellar Radius | 1.4914 R☉ |
| Stellar Mass | 1.1500 M☉ |
| Bolometric Luminosity | 2.77 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 7.650 · G: 7.511 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 8.431 days |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.63 g/cm³ (18 km/s vesc) |
| Insolation Flux | 383.1101 S⊕ (~521,413 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 201.800 LY (61.870 pc) |