Kepler-63 b
Kepler-63 b is a hot Jupiter orbiting Kepler-63 in the constellation Cygnus. It lies about 633 light-years from Earth and was discovered in 2013 using the transit method.
How Big Is Kepler-63 b?
Kepler-63 b has a radius of 6.11 times that of Earth, or 0.55 times the radius of Jupiter. Its mass is 120 times that of Earth, giving it a density of 3.00 g/cm³ — between that of rocky and gaseous planets.
Is Kepler-63 b in the Habitable Zone?
Kepler-63 b orbits inside the inner edge of the habitable zone of Kepler-63. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-63: 0.634–1.502 AU (conservative: 0.803–1.424 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-63 b — one full orbit around Kepler-63 — lasts 9.43 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.080 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.45), swinging dramatically closer to and farther from its star.
How Was Kepler-63 b Discovered?
Kepler-63 b was discovered in 2013 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-63 b?
Kepler-63 b is 632.9 light-years (194.0 parsecs) from Earth. Light arriving here tonight left the planet around the year 1394. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 11,139,040 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-63 b scores 0.14, ranking #4,257 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-63
Kepler-63
- Surface temperature
- 5,576 K (Sun: 5,772 K)
- Mass
- 0.98 M☉
- Radius
- 0.90 R☉
- Luminosity
- 0.6966 L☉
- Age
- 0.2 billion years (Sun: 4.6)
Planetary System
Kepler-63 b is the only planet known to orbit Kepler-63 so far.
Kepler-63 b — Complete Data
| Radius | 6.110 Earth radii (0.545 Jupiter radii) |
|---|---|
| Mass | 120.00 Earth masses (0.378 Jupiter masses) |
| Density | 3.00 g/cm³ (Earth: 5.51) |
| Orbital period | 9.43 days |
| Orbital distance | 0.080 AU |
| Eccentricity | 0.450 |
| Earth Similarity Index | 0.14 |
| Distance from Earth | 632.9 light-years (194.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2013 |
Data: NASA Exoplanet Archive, last updated 2019-12-02. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-63 b
Is Kepler-63 b habitable?
No — Kepler-63 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-63 b?
Kepler-63 b is about 633 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 11,139,040 years to get there.
How big is Kepler-63 b compared to Earth?
Kepler-63 b has 6.11 times the radius of Earth and about 120 times its mass.
How long is a year on Kepler-63 b?
One orbit around Kepler-63 takes 9.4 Earth days — short enough that 39 of its years would fit into one Earth year.
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