Kepler-688 b
Kepler-688 b is a hot Jupiter orbiting Kepler-688 in the constellation Cygnus. It lies about 4,428 light-years from Earth and was discovered in 2016 using the transit method.
How Big Is Kepler-688 b?
Kepler-688 b has a radius of 9.76 times that of Earth, or 0.87 times the radius of Jupiter.
Is Kepler-688 b in the Habitable Zone?
The position of Kepler-688 b relative to the habitable zone of Kepler-688 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-688: 0.707–1.670 AU (conservative: 0.896–1.583 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-688 b — one full orbit around Kepler-688 — lasts 3.90 Earth days, shorter than Mercury's 88-day year.
How Was Kepler-688 b Discovered?
Kepler-688 b was discovered in 2016 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-688 b?
Kepler-688 b is 4,428.4 light-years (1,357.8 parsecs) from Earth. Light arriving here tonight left the planet about 4,428 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 77,939,840 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-688 b scores 0.09, ranking #4,514 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-688
Kepler-688
- Surface temperature
- 5,715 K (Sun: 5,772 K)
- Mass
- 0.98 M☉
- Radius
- 0.96 R☉
- Age
- 4.3 billion years (Sun: 4.6)
Planetary System
Kepler-688 b is the only planet known to orbit Kepler-688 so far.
Kepler-688 b — Complete Data
| Radius | 9.760 Earth radii (0.871 Jupiter radii) |
|---|---|
| Orbital period | 3.90 days |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 4,428.4 light-years (1,357.8 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2016 |
Data: NASA Exoplanet Archive, last updated 2016-05-06. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-688 b
Is Kepler-688 b habitable?
Kepler-688 b is not known to orbit within the habitable zone of Kepler-688, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is Kepler-688 b?
Kepler-688 b is about 4,428 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 77,939,840 years to get there.
How big is Kepler-688 b compared to Earth?
Kepler-688 b has 9.76 times the radius of Earth.
How long is a year on Kepler-688 b?
One orbit around Kepler-688 takes 3.9 Earth days — short enough that 94 of its years would fit into one Earth year.
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