TOI-1839 b
Astrophysical Synthesis & Habitability Characterization
TOI-1839 b is a confirmed sub-neptune exoplanet orbiting the star TOI-1839, located approximately 378.6 light-years (116.09 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 0.0547% across the stellar disk), this world measures 2.27 Earth radii and has a measured mass of 7.1 Earth masses. Combining its mass and radius yields a mean bulk density of 3.35 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.38 g⊕ (13.53 m/s²), and an escape velocity of 19.8 km/s.
In its orbital architecture around TOI-1839, TOI-1839 b completes one full revolution every 1.424 Earth days at a semi-major axis of 0.02355 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 179.9 km/s (compared to Earth's 29.8 km/s).
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1585 K (+1312°C / +2394°F) and receiving 1,051.00 S⊕ (~1,430,411 W/m²), TOI-1839 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1839 is classified as a solar-type yellow star of spectral type G9 V with an effective photospheric temperature of 5,347 K, a radius of 0.89 R☉, a mass of 0.86 M☉, an estimated bolometric luminosity of 0.581 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.1 Gyr and a metallicity of [Fe/H] = 0.09 dex (metal-rich relative to the Sun). From Earth, TOI-1839 shines at apparent V-band magnitude 10.9 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-1839 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-1839 b sharing its stellar neighborhood alongside TOI-1839 c.
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-1839 |
| Spectral Type | G9 V |
| Effective Temp (Teff) | 5,347 K |
| Stellar Radius | 0.8900 R☉ |
| Stellar Mass | 0.8600 M☉ |
| Bolometric Luminosity | 0.581 L☉ |
| Metallicity [Fe/H] | 0.090 dex |
| Stellar Age | 4.100 Gyr |
| Apparent Magnitude | V: 10.900 · G: 10.727 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.023550 AU |
| Orbital Period | 1.424 days |
| Mean Orbital Velocity | 179.9 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 87.8000° |
| Mean Bulk Density | 3.35 g/cm³ (19.8 km/s vesc) |
| Insolation Flux | 1051.0000 S⊕ (~1,430,411 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 378.600 LY (116.086 pc) |