TOI-1386 b
Astrophysical Synthesis & Habitability Characterization
TOI-1386 b is a confirmed gas giant exoplanet orbiting the star TOI-1386, located approximately 479 light-years (146.86 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 0.31% across the stellar disk), this world measures 6.216 Earth radii (0.55 Jupiter radii) and has a measured mass of 45.8 Earth masses (0.14 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.05 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 30.4 km/s.
In its orbital architecture around TOI-1386, TOI-1386 b completes one full revolution every 25.84 Earth days at a semi-major axis of 0.173 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 72.8 km/s (compared to Earth's 29.8 km/s). 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 615 K (+342°C / +648°F) and receiving 34.68 S⊕ (~47,199 W/m²), TOI-1386 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1386 is classified as a solar-type yellow star of spectral type G5V with an effective photospheric temperature of 5,735 K, a radius of 1.0235 R☉, a mass of 1.0363 M☉, an estimated bolometric luminosity of 1.017 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.2 Gyr and a metallicity of [Fe/H] = 0.149 dex (metal-rich relative to the Sun). From Earth, TOI-1386 shines at apparent V-band magnitude 10.61 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The TOI-1386 system is a multi-planet architecture hosting 2 confirmed worlds, with TOI-1386 b sharing its stellar neighborhood alongside TOI-1386 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-1386 |
| Spectral Type | G5V |
| Effective Temp (Teff) | 5,735 K |
| Stellar Radius | 1.0235 R☉ |
| Stellar Mass | 1.0363 M☉ |
| Bolometric Luminosity | 1.017 L☉ |
| Metallicity [Fe/H] | 0.149 dex |
| Stellar Age | 3.200 Gyr |
| Apparent Magnitude | V: 10.610 · G: 10.507 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.173000 AU |
| Orbital Period | 25.84 days |
| Mean Orbital Velocity | 72.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.6900° |
| Mean Bulk Density | 1.05 g/cm³ (30.4 km/s vesc) |
| Insolation Flux | 34.6800 S⊕ (~47,199 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 479.000 LY (146.858 pc) |