Kepler-684 b
Kepler-684 b is a sub-Neptune orbiting Kepler-684 in the constellation Lyra. It lies about 5,647 light-years from Earth and was discovered in 2016 using the transit method.
How Big Is Kepler-684 b?
Kepler-684 b has a radius of 3.36 times that of Earth.
Is Kepler-684 b in the Habitable Zone?
The position of Kepler-684 b relative to the habitable zone of Kepler-684 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-684: 0.593–1.409 AU (conservative: 0.751–1.336 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-684 b — one full orbit around Kepler-684 — lasts 6.77 Earth days, shorter than Mercury's 88-day year.
How Was Kepler-684 b Discovered?
Kepler-684 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-684 b?
Kepler-684 b is 5,646.6 light-years (1,731.3 parsecs) from Earth. Light arriving here tonight left the planet about 5,647 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 99,380,160 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-684 b scores 0.20, ranking #3,891 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-684
Kepler-684
- Surface temperature
- 5,493 K (Sun: 5,772 K)
- Mass
- 0.89 M☉
- Radius
- 0.86 R☉
- Age
- 4.4 billion years (Sun: 4.6)
Planetary System
Kepler-684 b is the only planet known to orbit Kepler-684 so far.
Kepler-684 b — Complete Data
| Radius | 3.360 Earth radii (0.300 Jupiter radii) |
|---|---|
| Orbital period | 6.77 days |
| Earth Similarity Index | 0.20 |
| Distance from Earth | 5,646.6 light-years (1,731.3 parsecs) |
| Constellation | Lyra |
| 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-684 b
Is Kepler-684 b habitable?
Kepler-684 b is not known to orbit within the habitable zone of Kepler-684, and as a sub-Neptune it is an unlikely candidate for life as we know it.
How far away is Kepler-684 b?
Kepler-684 b is about 5,647 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 99,380,160 years to get there.
How big is Kepler-684 b compared to Earth?
Kepler-684 b has 3.36 times the radius of Earth.
How long is a year on Kepler-684 b?
One orbit around Kepler-684 takes 6.8 Earth days — short enough that 54 of its years would fit into one Earth year.
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