Kepler-139 e
Kepler-139 e is a cold gas giant orbiting Kepler-139 in the constellation Lyra. It lies about 1,275 light-years from Earth and was discovered in 2023 using the radial velocity method.
Is Kepler-139 e in the Habitable Zone?
Kepler-139 e orbits beyond the outer edge of the habitable zone of Kepler-139. At that distance, any surface water would almost certainly be frozen.
Habitable zone of Kepler-139: 0.924–2.189 AU (conservative: 1.171–2.076 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Orbit and Year Length
A year on Kepler-139 e — one full orbit around Kepler-139 — lasts 2,047.6 Earth days, longer than an Earth year. It orbits at an average distance of 3.236 AU. Its orbit is nearly circular (eccentricity 0.013).
How Was Kepler-139 e Discovered?
Kepler-139 e was discovered in 2023 using the radial velocity method, with observations from W. M. Keck Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is Kepler-139 e?
Kepler-139 e is 1,275.4 light-years (391.0 parsecs) from Earth. Light arriving here tonight left the planet about 1,275 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 22,447,040 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. Kepler-139 e scores 0.16, ranking #4,170 of 5,565 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-139
Kepler-139
- Surface temperature
- 5,594 K (Sun: 5,772 K)
- Radius
- 1.30 R☉
The Kepler-139 Planetary System
Kepler-139 e is one of 5 known planets in the Kepler-139 system. Its siblings:
- Kepler-139 b (Mini Neptune)
- Kepler-139 c (Sub Neptune)
- Kepler-139 d (Super Earth)
- Kepler-139 f (Neptune-like)
Kepler-139 e — Complete Data
| Mass (best estimate) | 426.12 Earth masses |
|---|---|
| Orbital period | 2,047.64 days |
| Orbital distance | 3.236 AU |
| Eccentricity | 0.013 |
| Earth Similarity Index | 0.16 |
| Distance from Earth | 1,275.4 light-years (391.0 parsecs) |
| Constellation | Lyra |
| Discovery method | Radial Velocity |
| Discovery facility | W. M. Keck Observatory |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2024-02-16. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-139 e
Is Kepler-139 e habitable?
No — Kepler-139 e orbits outside the habitable zone of Kepler-139 and is likely too cold for liquid water on its surface.
How far away is Kepler-139 e?
Kepler-139 e is about 1,275 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 22,447,040 years to get there.
How long is a year on Kepler-139 e?
One orbit around Kepler-139 takes 2,047.6 Earth days.
Explore Kepler-139 e in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
