Kepler-11 d
Kepler-11 d is a puffy low-density planet orbiting Kepler-11 in the constellation Cygnus. It lies about 2,108 light-years from Earth and was discovered in 2010 using the transit method.
How Big Is Kepler-11 d?
Kepler-11 d has a radius of 3.12 times that of Earth. Its mass is 7.3 times that of Earth, giving it a density of 1.28 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-11 d in the Habitable Zone?
Kepler-11 d orbits inside the inner edge of the habitable zone of Kepler-11. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-11: 0.773–1.827 AU (conservative: 0.979–1.732 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-11 d — one full orbit around Kepler-11 — lasts 22.7 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.155 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.004).
How Was Kepler-11 d Discovered?
Kepler-11 d was discovered in 2010 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-11 d?
Kepler-11 d is 2,108.1 light-years (646.3 parsecs) from Earth. Light arriving here tonight left the planet about 2,108 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 37,102,560 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-11 d scores 0.23, ranking #3,547 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-11
Kepler-11
- Surface temperature
- 5,663 K (Sun: 5,772 K)
- Mass
- 0.96 M☉
- Radius
- 1.07 R☉
- Age
- 8.5 billion years (Sun: 4.6)
The Kepler-11 Planetary System
Kepler-11 d is one of 6 known planets in the Kepler-11 system. Its siblings:
- Kepler-11 b (Mini Neptune)
- Kepler-11 c (Puffy Planet)
- Kepler-11 e (Neptune-like)
- Kepler-11 f (Puffy Planet)
- Kepler-11 g (Super Earth)
Kepler-11 d — Complete Data
| Radius | 3.120 Earth radii (0.278 Jupiter radii) |
|---|---|
| Mass | 7.30 Earth masses (0.023 Jupiter masses) |
| Density | 1.28 g/cm³ (Earth: 5.51) |
| Orbital period | 22.68 days |
| Orbital distance | 0.155 AU |
| Eccentricity | 0.004 |
| Earth Similarity Index | 0.23 |
| Distance from Earth | 2,108.1 light-years (646.3 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2010 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-11 d
Is Kepler-11 d habitable?
No — Kepler-11 d orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-11 d?
Kepler-11 d is about 2,108 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 37,102,560 years to get there.
How big is Kepler-11 d compared to Earth?
Kepler-11 d has 3.12 times the radius of Earth and about 7.3 times its mass.
How long is a year on Kepler-11 d?
One orbit around Kepler-11 takes 22.7 Earth days — short enough that 16 of its years would fit into one Earth year.
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