KOI-134 c
Astrophysical Synthesis & Habitability Characterization
KOI-134 c is a confirmed gas giant exoplanet orbiting the star KOI-134, located approximately 3780.8 light-years (1159.21 parsecs) from the Solar System. First announced in 2025 by Kepler using the Transit Timing Variations detection technique (producing an estimated primary transit depth of 0.2941% across the stellar disk), this world measures 9.86 Earth radii (0.88 Jupiter radii) and has a measured mass of 69.922 Earth masses (0.22 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.4 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.72 g⊕ (7.06 m/s²), and an escape velocity of 29.8 km/s.
In its orbital architecture around KOI-134, KOI-134 c completes one full revolution every 33.95 Earth days at a semi-major axis of 0.2305 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 73.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.24 carries the world between 0.1752 AU at periapsis and 0.2858 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 799 K (+526°C / +979°F) and receiving 79.05 S⊕ (~107,588 W/m²), KOI-134 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star KOI-134 is classified as a warm F-type star of spectral type F9V with an effective photospheric temperature of 6,160 K, a radius of 1.667 R☉, a mass of 1.407 M☉, an estimated bolometric luminosity of 3.59 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.4 Gyr and a metallicity of [Fe/H] = 0.427 dex (metal-rich relative to the Sun). From Earth, KOI-134 shines at apparent V-band magnitude 13.773 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The KOI-134 system is a multi-planet architecture hosting 2 confirmed worlds, with KOI-134 c sharing its stellar neighborhood alongside KOI-134 b.
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: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | KOI-134 |
| Spectral Type | F9V |
| Effective Temp (Teff) | 6,160 K |
| Stellar Radius | 1.6670 R☉ |
| Stellar Mass | 1.4070 M☉ |
| Bolometric Luminosity | 3.59 L☉ |
| Metallicity [Fe/H] | 0.427 dex |
| Stellar Age | 2.400 Gyr |
| Apparent Magnitude | V: 13.773 · G: 13.632 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.230500 AU |
| Orbital Period | 33.95 days |
| Mean Orbital Velocity | 73.9 km/s |
| Orbital Eccentricity (e) | 0.24000 |
| Orbital Inclination (i) | 75.0000° |
| Mean Bulk Density | 0.4 g/cm³ (29.8 km/s vesc) |
| Insolation Flux | 79.0510 S⊕ (~107,588 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3780.800 LY (1159.210 pc) |