TOI-1439 b
Astrophysical Synthesis & Habitability Characterization
TOI-1439 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1439, located approximately 751.2 light-years (230.31 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 0.0578% across the stellar disk), this world measures 4.243 Earth radii (0.38 Jupiter radii) and has a measured mass of 38.5 Earth masses (0.12 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.78 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 2.14 g⊕ (20.99 m/s²), and an escape velocity of 33.7 km/s.
In its orbital architecture around TOI-1439, TOI-1439 b completes one full revolution every 27.644 Earth days at a semi-major axis of 0.192 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 75.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.157 carries the world between 0.1619 AU at periapsis and 0.2221 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 748 K (+475°C / +887°F) and receiving 68.44 S⊕ (~93,141 W/m²), TOI-1439 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1439 is classified as a stellar host with an effective photospheric temperature of 5,841 K, a radius of 1.6184 R☉, a mass of 1.2313 M☉, an estimated bolometric luminosity of 2.735 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.6 Gyr and a metallicity of [Fe/H] = 0.226 dex (metal-rich relative to the Sun). From Earth, TOI-1439 shines at apparent V-band magnitude 10.55 (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-1439 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,841 K |
| Stellar Radius | 1.6184 R☉ |
| Stellar Mass | 1.2313 M☉ |
| Bolometric Luminosity | 2.735 L☉ |
| Metallicity [Fe/H] | 0.226 dex |
| Stellar Age | 4.600 Gyr |
| Apparent Magnitude | V: 10.550 · G: 10.417 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.192000 AU |
| Orbital Period | 27.644 days |
| Mean Orbital Velocity | 75.6 km/s |
| Orbital Eccentricity (e) | 0.15700 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.78 g/cm³ (33.7 km/s vesc) |
| Insolation Flux | 68.4355 S⊕ (~93,141 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 751.200 LY (230.306 pc) |