KOI-134 b
KOI-134 b is a cold gas giant orbiting the F9V star KOI-134 in the constellation Cygnus. It lies about 3,781 light-years from Earth and was discovered in 2025 using the transit method.
How Big Is KOI-134 b?
KOI-134 b has a radius of 12.04 times that of Earth, or 1.07 times the radius of Jupiter. Its mass is 346 times that of Earth.
Is KOI-134 b in the Habitable Zone?
KOI-134 b orbits inside the inner edge of the habitable zone of KOI-134. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of KOI-134: 1.503–3.509 AU (conservative: 1.903–3.327 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on KOI-134 b
The equilibrium temperature of KOI-134 b is about 659 K (386 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 45.00 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on KOI-134 b — one full orbit around KOI-134 — lasts 67.1 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.363 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.16).
How Was KOI-134 b Discovered?
KOI-134 b was discovered in 2025 using the transit method, with observations from Kepler.
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is KOI-134 b?
KOI-134 b is 3,780.8 light-years (1,159.2 parsecs) from Earth. Light arriving here tonight left the planet about 3,781 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 66,542,080 years to make the journey.
The Host Star: KOI-134
KOI-134
- Spectral type
- F9V
- Surface temperature
- 6,160 K (Sun: 5,772 K)
- Mass
- 1.41 M☉
- Radius
- 1.67 R☉
- Luminosity
- 4.2000 L☉
The KOI-134 Planetary System
KOI-134 b is one of 2 known planets in the KOI-134 system. Its siblings:
- KOI-134 c (Cold Gas Giant)
KOI-134 b — Complete Data
| Radius | 12.038 Earth radii (1.074 Jupiter radii) |
|---|---|
| Mass | 346.43 Earth masses (1.090 Jupiter masses) |
| Orbital period | 67.13 days |
| Orbital distance | 0.363 AU |
| Eccentricity | 0.160 |
| Equilibrium temperature | 659 K (386 °C) |
| Stellar irradiation | 45.00× Earth |
| Distance from Earth | 3,780.8 light-years (1,159.2 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2025-07-17. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About KOI-134 b
Is KOI-134 b habitable?
No — KOI-134 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is KOI-134 b?
KOI-134 b is about 3,781 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 66,542,080 years to get there.
How big is KOI-134 b compared to Earth?
KOI-134 b has 12.04 times the radius of Earth and about 346 times its mass.
How long is a year on KOI-134 b?
One orbit around KOI-134 takes 67.1 Earth days.
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