Kepler-82 b
Kepler-82 b is a Neptune-like planet orbiting Kepler-82 in the constellation Cygnus. It lies about 2,950 light-years from Earth and was discovered in 2012 using the transit method.
How Big Is Kepler-82 b?
Kepler-82 b has a radius of 4.07 times that of Earth. Its mass is 12.2 times that of Earth, giving it a density of 0.98 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-82 b in the Habitable Zone?
The position of Kepler-82 b relative to the habitable zone of Kepler-82 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on Kepler-82 b — one full orbit around Kepler-82 — lasts 26.4 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.168 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.003).
How Was Kepler-82 b Discovered?
Kepler-82 b was discovered in 2012 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-82 b?
Kepler-82 b is 2,949.5 light-years (904.3 parsecs) from Earth. Light arriving here tonight left the planet about 2,950 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 51,911,200 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-82 b scores 0.22, ranking #3,607 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-82
Kepler-82
- Mass
- 0.91 M☉
- Radius
- 0.90 R☉
The Kepler-82 Planetary System
Kepler-82 b is one of 5 known planets in the Kepler-82 system. Its siblings:
- Kepler-82 c (Neptune-like)
- Kepler-82 d (Super Earth)
- Kepler-82 e (Mini Neptune)
- Kepler-82 f (Neptune-like)
Kepler-82 b — Complete Data
| Radius | 4.070 Earth radii (0.363 Jupiter radii) |
|---|---|
| Mass | 12.15 Earth masses (0.038 Jupiter masses) |
| Density | 0.98 g/cm³ (Earth: 5.51) |
| Orbital period | 26.44 days |
| Orbital distance | 0.168 AU |
| Eccentricity | 0.003 |
| Earth Similarity Index | 0.22 |
| Distance from Earth | 2,949.5 light-years (904.3 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2012 |
Data: NASA Exoplanet Archive, last updated 2019-07-19. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-82 b
Is Kepler-82 b habitable?
Kepler-82 b is not known to orbit within the habitable zone of Kepler-82, and as a Neptune-like planet it is an unlikely candidate for life as we know it.
How far away is Kepler-82 b?
Kepler-82 b is about 2,950 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 51,911,200 years to get there.
How big is Kepler-82 b compared to Earth?
Kepler-82 b has 4.07 times the radius of Earth and about 12.2 times its mass.
How long is a year on Kepler-82 b?
One orbit around Kepler-82 takes 26.4 Earth days — short enough that 14 of its years would fit into one Earth year.
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