Kepler-29 b
Kepler-29 b is a mini-Neptune orbiting Kepler-29 in the constellation Cygnus. It lies about 2,715 light-years from Earth and was discovered in 2011 using the transit method.
How Big Is Kepler-29 b?
Kepler-29 b has a radius of 2.55 times that of Earth. Its mass is 5.0 times that of Earth, giving it a density of 1.65 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-29 b in the Habitable Zone?
The position of Kepler-29 b relative to the habitable zone of Kepler-29 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-29: 0.487–1.161 AU (conservative: 0.617–1.101 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-29 b
Kepler-29 b receives 55.90 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on Kepler-29 b — one full orbit around Kepler-29 — lasts 10.3 Earth days, shorter than Mercury's 88-day year.
How Was Kepler-29 b Discovered?
Kepler-29 b was discovered in 2011 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-29 b?
Kepler-29 b is 2,715.4 light-years (832.5 parsecs) from Earth. Light arriving here tonight left the planet about 2,715 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 47,791,040 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-29 b scores 0.25, ranking #3,112 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-29
Kepler-29
- Surface temperature
- 5,378 K (Sun: 5,772 K)
- Mass
- 0.76 M☉
- Radius
- 0.73 R☉
The Kepler-29 Planetary System
Kepler-29 b is one of 2 known planets in the Kepler-29 system. Its siblings:
- Kepler-29 c (Mini Neptune)
Kepler-29 b — Complete Data
| Radius | 2.550 Earth radii (0.227 Jupiter radii) |
|---|---|
| Mass | 5.00 Earth masses (0.016 Jupiter masses) |
| Density | 1.65 g/cm³ (Earth: 5.51) |
| Orbital period | 10.34 days |
| Stellar irradiation | 55.90× Earth |
| Earth Similarity Index | 0.25 |
| Distance from Earth | 2,715.4 light-years (832.5 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2011 |
Data: NASA Exoplanet Archive, last updated 2020-05-01. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-29 b
Is Kepler-29 b habitable?
Kepler-29 b is not known to orbit within the habitable zone of Kepler-29, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is Kepler-29 b?
Kepler-29 b is about 2,715 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 47,791,040 years to get there.
How big is Kepler-29 b compared to Earth?
Kepler-29 b has 2.55 times the radius of Earth and about 5.0 times its mass.
How long is a year on Kepler-29 b?
One orbit around Kepler-29 takes 10.3 Earth days — short enough that 35 of its years would fit into one Earth year.
Explore Kepler-29 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
