Kepler-725 c
Kepler-725 c is a super-Earth orbiting Kepler-725 in the constellation Lyra. It lies about 2,474 light-years from Earth and was discovered in 2025 using the transit timing variations method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.
Is Kepler-725 c in the Habitable Zone?
Kepler-725 c orbits within the optimistic habitable zone of Kepler-725 — the broader region where liquid water might be possible under favorable atmospheric conditions.
Habitable zone of Kepler-725: 0.589–1.403 AU (conservative: 0.746–1.330 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 ›
Temperature on Kepler-725 c
The equilibrium temperature of Kepler-725 c is about 268 K (-5 °C) — in a range broadly comparable to Earth, whose equilibrium temperature is 255 K. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 1.40 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on Kepler-725 c — one full orbit around Kepler-725 — lasts 207.5 Earth days, between the years of Mercury (88 days) and Earth (365 days). It orbits at an average distance of 0.674 AU — comparable to the inner Solar System. Its orbit is highly elliptical (eccentricity 0.44), swinging dramatically closer to and farther from its star.
How Was Kepler-725 c Discovered?
Kepler-725 c was discovered in 2025 using the transit timing variations method, with observations from Kepler.
Transit timing variations reveal a planet through its gravitational tug on a sibling planet, which makes that sibling's transits arrive slightly early or late. The pattern of these deviations betrays the hidden planet's mass and orbit.
How Far Away Is Kepler-725 c?
Kepler-725 c is 2,473.8 light-years (758.5 parsecs) from Earth. Light arriving here tonight left the planet about 2,474 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 43,538,880 years to make the journey.
The Host Star: Kepler-725
Kepler-725
- Surface temperature
- 5,395 K (Sun: 5,772 K)
- Mass
- 0.95 M☉
- Radius
- 0.88 R☉
- Age
- 1.6 billion years (Sun: 4.6)
The Kepler-725 Planetary System
Kepler-725 c is one of 2 known planets in the Kepler-725 system. Its siblings:
- Kepler-725 b (Cold Gas Giant)
Kepler-725 c — Complete Data
| Mass | 9.70 Earth masses (0.031 Jupiter masses) |
|---|---|
| Orbital period | 207.54 days |
| Orbital distance | 0.674 AU |
| Eccentricity | 0.436 |
| Equilibrium temperature | 268 K (-5 °C) |
| Stellar irradiation | 1.40× Earth |
| Distance from Earth | 2,473.8 light-years (758.5 parsecs) |
| Constellation | Lyra |
| Discovery method | Transit Timing Variations |
| Discovery facility | Kepler |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2025-06-26. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-725 c
Is Kepler-725 c habitable?
Kepler-725 c orbits within the habitable zone of Kepler-725, the region where liquid water could exist on a planet's surface. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.
How far away is Kepler-725 c?
Kepler-725 c is about 2,474 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 43,538,880 years to get there.
How long is a year on Kepler-725 c?
One orbit around Kepler-725 takes 207.5 Earth days.
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