Kepler-46 b
Kepler-46 b is a cold gas giant orbiting Kepler-46 in the constellation Lyra. It lies about 2,534 light-years from Earth and was discovered in 2012 using the transit method.
How Big Is Kepler-46 b?
Kepler-46 b has a radius of 9.06 times that of Earth, or 0.81 times the radius of Jupiter. Its mass is 1,907 times that of Earth, giving it a density of 14.00 g/cm³ — comparable to rocky planets like Earth (5.51 g/cm³).
Is Kepler-46 b in the Habitable Zone?
Kepler-46 b orbits inside the inner edge of the habitable zone of Kepler-46. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-46: 0.580–1.393 AU (conservative: 0.734–1.321 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on Kepler-46 b
The equilibrium temperature of Kepler-46 b is about 543 K (270 °C) — hotter than anywhere on Earth. 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-46 b — one full orbit around Kepler-46 — lasts 33.6 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.197 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.010).
How Was Kepler-46 b Discovered?
Kepler-46 b was discovered in 2012 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-46 b?
Kepler-46 b is 2,534.4 light-years (777.1 parsecs) from Earth. Light arriving here tonight left the planet about 2,534 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 44,605,440 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-46 b scores 0.16, ranking #4,121 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-46
Kepler-46
- Surface temperature
- 5,155 K (Sun: 5,772 K)
- Mass
- 0.90 M☉
- Radius
- 0.94 R☉
- Luminosity
- 0.5559 L☉
- Age
- 9.7 billion years (Sun: 4.6)
The Kepler-46 Planetary System
Kepler-46 b is one of 3 known planets in the Kepler-46 system. Its siblings:
- Kepler-46 c (Cold Gas Giant)
- Kepler-46 d (Super Earth)
Kepler-46 b — Complete Data
| Radius | 9.057 Earth radii (0.808 Jupiter radii) |
|---|---|
| Mass | 1,907.00 Earth masses (6.000 Jupiter masses) |
| Density | 14.00 g/cm³ (Earth: 5.51) |
| Orbital period | 33.60 days |
| Orbital distance | 0.197 AU |
| Eccentricity | 0.010 |
| Equilibrium temperature | 543 K (270 °C) |
| Earth Similarity Index | 0.16 |
| Distance from Earth | 2,534.4 light-years (777.1 parsecs) |
| Constellation | Lyra |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2012 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-46 b
Is Kepler-46 b habitable?
No — Kepler-46 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-46 b?
Kepler-46 b is about 2,534 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 44,605,440 years to get there.
How big is Kepler-46 b compared to Earth?
Kepler-46 b has 9.06 times the radius of Earth and about 1,907 times its mass.
How long is a year on Kepler-46 b?
One orbit around Kepler-46 takes 33.6 Earth days — short enough that 11 of its years would fit into one Earth year.
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