TOI-1136 g
Astrophysical Synthesis & Habitability Characterization
TOI-1136 g is a confirmed sub-neptune exoplanet orbiting the star TOI-1136, located approximately 275.7 light-years (84.54 parsecs) from the Solar System. First announced in 2022 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.0574% across the stellar disk), this world measures 2.53 Earth radii and has a measured mass of 5.6 Earth masses. Combining its mass and radius yields a mean bulk density of 1.91 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.87 g⊕ (8.53 m/s²), and an escape velocity of 16.6 km/s.
In its orbital architecture around TOI-1136, TOI-1136 g completes one full revolution every 39.545 Earth days at a semi-major axis of 0.229 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 63 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.04 (ranging from 0.2198 AU at periapsis to 0.2382 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 574 K (+301°C / +574°F) and receiving 17.92 S⊕ (~24,396 W/m²), TOI-1136 g orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-1136 is classified as a stellar host with an effective photospheric temperature of 5,770 K, a radius of 0.968 R☉, a mass of 1.022 M☉, an estimated bolometric luminosity of 0.932 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.7 Gyr and a metallicity of [Fe/H] = 0.07 dex (metal-rich relative to the Sun). From Earth, TOI-1136 shines at apparent V-band magnitude 9.534 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The TOI-1136 system is a multi-planet architecture hosting 6 confirmed worlds, with TOI-1136 g sharing its stellar neighborhood alongside TOI-1136 b, TOI-1136 c, TOI-1136 d, TOI-1136 e, TOI-1136 f.
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-1136 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,770 K |
| Stellar Radius | 0.9680 R☉ |
| Stellar Mass | 1.0220 M☉ |
| Bolometric Luminosity | 0.932 L☉ |
| Metallicity [Fe/H] | 0.070 dex |
| Stellar Age | 0.700 Gyr |
| Apparent Magnitude | V: 9.534 · G: 9.368 |
| System Architecture | 1 Star, 6 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.229000 AU |
| Orbital Period | 39.545 days |
| Mean Orbital Velocity | 63 km/s |
| Orbital Eccentricity (e) | 0.04000 |
| Orbital Inclination (i) | 89.5000° |
| Mean Bulk Density | 1.91 g/cm³ (16.6 km/s vesc) |
| Insolation Flux | 17.9249 S⊕ (~24,396 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 275.700 LY (84.536 pc) |