Kepler-1491 c
Kepler-1491 c is a mini-Neptune orbiting Kepler-1491 in the constellation Cygnus. It lies about 6,737 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is Kepler-1491 c?
Kepler-1491 c has a radius of 2.44 times that of Earth.
Is Kepler-1491 c in the Habitable Zone?
Kepler-1491 c orbits inside the inner edge of the habitable zone of Kepler-1491. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-1491: 0.732–1.728 AU (conservative: 0.928–1.638 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-1491 c
The equilibrium temperature of Kepler-1491 c is about 530 K (257 °C) — hotter than anywhere on Earth. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 18.66 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on Kepler-1491 c — one full orbit around Kepler-1491 — lasts 61.6 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.305 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-1491 c Discovered?
Kepler-1491 c was discovered in 2023 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 Kepler-1491 c?
Kepler-1491 c is 6,737.0 light-years (2,065.6 parsecs) from Earth. Light arriving here tonight left the planet about 6,737 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 118,571,200 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-1491 c scores 0.28, ranking #2,095 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-1491
Kepler-1491
- Surface temperature
- 5,728 K (Sun: 5,772 K)
- Mass
- 1.00 M☉
- Radius
- 0.99 R☉
- Age
- 4.6 billion years (Sun: 4.6)
The Kepler-1491 Planetary System
Kepler-1491 c is one of 2 known planets in the Kepler-1491 system. Its siblings:
- Kepler-1491 b (Super Earth)
Kepler-1491 c — Complete Data
| Radius | 2.440 Earth radii (0.218 Jupiter radii) |
|---|---|
| Orbital period | 61.57 days |
| Orbital distance | 0.305 AU |
| Equilibrium temperature | 530 K (257 °C) |
| Stellar irradiation | 18.66× Earth |
| Earth Similarity Index | 0.28 |
| Distance from Earth | 6,737.0 light-years (2,065.6 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2017-05-08. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-1491 c
Is Kepler-1491 c habitable?
No — Kepler-1491 c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-1491 c?
Kepler-1491 c is about 6,737 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 118,571,200 years to get there.
How big is Kepler-1491 c compared to Earth?
Kepler-1491 c has 2.44 times the radius of Earth.
How long is a year on Kepler-1491 c?
One orbit around Kepler-1491 takes 61.6 Earth days.
Explore Kepler-1491 c in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
