Kepler-7 b
Kepler-7 b is a hot Jupiter orbiting Kepler-7 in the constellation Lyra. It lies about 3,009 light-years from Earth and was discovered in 2009 using the transit method.
How Big Is Kepler-7 b?
Kepler-7 b has a radius of 18.18 times that of Earth, or 1.62 times the radius of Jupiter. Its mass is 140 times that of Earth, giving it a density of 0.14 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-7 b in the Habitable Zone?
Kepler-7 b orbits inside the inner edge of the habitable zone of Kepler-7. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-7: 1.541–3.617 AU (conservative: 1.952–3.429 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-7 b
The equilibrium temperature of Kepler-7 b is about 1,630 K (1,357 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C.
Orbit and Year Length
A year on Kepler-7 b — one full orbit around Kepler-7 — lasts 4.89 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.061 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-7 b Discovered?
Kepler-7 b was discovered in 2009 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-7 b?
Kepler-7 b is 3,009.0 light-years (922.6 parsecs) from Earth. Light arriving here tonight left the planet about 3,009 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 52,958,400 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-7 b scores 0.05, ranking #5,272 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-7
Kepler-7
- Surface temperature
- 5,933 K (Sun: 5,772 K)
- Mass
- 1.36 M☉
- Radius
- 1.97 R☉
Planetary System
Kepler-7 b is the only planet known to orbit Kepler-7 so far.
Kepler-7 b — Complete Data
| Radius | 18.181 Earth radii (1.622 Jupiter radii) |
|---|---|
| Mass | 140.16 Earth masses (0.441 Jupiter masses) |
| Density | 0.14 g/cm³ (Earth: 5.51) |
| Orbital period | 4.89 days |
| Orbital distance | 0.061 AU |
| Equilibrium temperature | 1,630 K (1,357 °C) |
| Earth Similarity Index | 0.05 |
| Distance from Earth | 3,009.0 light-years (922.6 parsecs) |
| Constellation | Lyra |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2009 |
Data: NASA Exoplanet Archive, last updated 2015-10-07. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-7 b
Is Kepler-7 b habitable?
No — Kepler-7 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-7 b?
Kepler-7 b is about 3,009 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 52,958,400 years to get there.
How big is Kepler-7 b compared to Earth?
Kepler-7 b has 18.18 times the radius of Earth and about 140 times its mass.
How long is a year on Kepler-7 b?
One orbit around Kepler-7 takes 4.9 Earth days — short enough that 75 of its years would fit into one Earth year.
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