TOI-6158 b
Astrophysical Synthesis & Habitability Characterization
TOI-6158 b is a confirmed gas giant exoplanet orbiting the star TOI-6158, located approximately 590.2 light-years (180.96 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 4.0123% across the stellar disk), this world measures 10.4 Earth radii (0.93 Jupiter radii) and has a measured mass of 135 Earth masses (0.42 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.66 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.25 g⊕ (12.26 m/s²), and an escape velocity of 40.3 km/s.
In its orbital architecture around TOI-6158, TOI-6158 b completes one full revolution every 3.045 Earth days at a semi-major axis of 0.03275 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 117 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.059 carries the world between 0.0308 AU at periapsis and 0.0347 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 636 K (+363°C / +685°F) and receiving 27.30 S⊕ (~37,155 W/m²), TOI-6158 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-6158 is classified as a low-mass red dwarf of spectral type M2 with an effective photospheric temperature of 3,467 K, a radius of 0.476 R☉, a mass of 0.503 M☉, an estimated bolometric luminosity of 0.029 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.11 dex (metal-rich relative to the Sun). From Earth, TOI-6158 shines at apparent V-band magnitude 16.29 (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-6158 |
| Spectral Type | M2 |
| Effective Temp (Teff) | 3,467 K |
| Stellar Radius | 0.4760 R☉ |
| Stellar Mass | 0.5030 M☉ |
| Bolometric Luminosity | 0.029 L☉ |
| Metallicity [Fe/H] | 0.110 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 16.290 · G: 15.753 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.032750 AU |
| Orbital Period | 3.045 days |
| Mean Orbital Velocity | 117 km/s |
| Orbital Eccentricity (e) | 0.05900 |
| Orbital Inclination (i) | 86.5100° |
| Mean Bulk Density | 0.66 g/cm³ (40.3 km/s vesc) |
| Insolation Flux | 27.3000 S⊕ (~37,155 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 590.200 LY (180.960 pc) |