Kepler-432 b
Kepler-432 b is a cold gas giant orbiting Kepler-432 in the constellation Cygnus. It lies about 2,766 light-years from Earth and was discovered in 2015 using the transit method.
How Big Is Kepler-432 b?
Kepler-432 b has a radius of 12.83 times that of Earth, or 1.15 times the radius of Jupiter. Its mass is 1,719 times that of Earth, giving it a density of 4.46 g/cm³ — between that of rocky and gaseous planets.
Is Kepler-432 b in the Habitable Zone?
Kepler-432 b orbits inside the inner edge of the habitable zone of Kepler-432. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-432: 2.377–5.748 AU (conservative: 3.011–5.450 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Orbit and Year Length
A year on Kepler-432 b — one full orbit around Kepler-432 — lasts 52.5 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.301 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.51), swinging dramatically closer to and farther from its star.
How Was Kepler-432 b Discovered?
Kepler-432 b was discovered in 2015 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-432 b?
Kepler-432 b is 2,765.9 light-years (848.0 parsecs) from Earth. Light arriving here tonight left the planet about 2,766 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 48,679,840 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-432 b scores 0.08, ranking #4,682 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-432
Kepler-432 b belongs to a system of 2 stars; it orbits Kepler-432.
Kepler-432
- Surface temperature
- 4,995 K (Sun: 5,772 K)
- Mass
- 1.32 M☉
- Radius
- 4.06 R☉
- Age
- 4.2 billion years (Sun: 4.6)
The Kepler-432 Planetary System
Kepler-432 b is one of 2 known planets in the Kepler-432 system. Its siblings:
- Kepler-432 c (Cold Gas Giant)
Kepler-432 b — Complete Data
| Radius | 12.834 Earth radii (1.145 Jupiter radii) |
|---|---|
| Mass | 1,719.46 Earth masses (5.410 Jupiter masses) |
| Density | 4.46 g/cm³ (Earth: 5.51) |
| Orbital period | 52.50 days |
| Orbital distance | 0.301 AU |
| Eccentricity | 0.513 |
| Earth Similarity Index | 0.08 |
| Distance from Earth | 2,765.9 light-years (848.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2015 |
Data: NASA Exoplanet Archive, last updated 2015-04-30. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-432 b
Is Kepler-432 b habitable?
No — Kepler-432 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-432 b?
Kepler-432 b is about 2,766 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 48,679,840 years to get there.
How big is Kepler-432 b compared to Earth?
Kepler-432 b has 12.83 times the radius of Earth and about 1,719 times its mass.
How long is a year on Kepler-432 b?
One orbit around Kepler-432 takes 52.5 Earth days.
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