Kepler-553 b
Kepler-553 b is a Neptune-like planet orbiting Kepler-553 in the constellation Cygnus. It lies about 2,376 light-years from Earth and was discovered in 2016 using the transit method.
How Big Is Kepler-553 b?
Kepler-553 b has a radius of 4.74 times that of Earth. Its mass is 116 times that of Earth.
Is Kepler-553 b in the Habitable Zone?
Kepler-553 b orbits inside the inner edge of the habitable zone of Kepler-553. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-553: 0.568–1.363 AU (conservative: 0.719–1.293 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on Kepler-553 b
The equilibrium temperature of Kepler-553 b is about 1,089 K (816 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 235 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on Kepler-553 b — one full orbit around Kepler-553 — lasts 4.03 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.048 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-553 b Discovered?
Kepler-553 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-553 b?
Kepler-553 b is 2,376.1 light-years (728.5 parsecs) from Earth. Light arriving here tonight left the planet about 2,376 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 41,819,360 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-553 b scores 0.16, ranking #4,122 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-553
Kepler-553
- Surface temperature
- 5,191 K (Sun: 5,772 K)
- Mass
- 0.89 M☉
- Radius
- 0.90 R☉
- Luminosity
- 0.5360 L☉
- Age
- 8.8 billion years (Sun: 4.6)
The Kepler-553 Planetary System
Kepler-553 b is one of 2 known planets in the Kepler-553 system. Its siblings:
- Kepler-553 c (Cold Gas Giant)
Kepler-553 b — Complete Data
| Radius | 4.741 Earth radii (0.423 Jupiter radii) |
|---|---|
| Mass | 116.01 Earth masses (0.365 Jupiter masses) |
| Orbital period | 4.03 days |
| Orbital distance | 0.048 AU |
| Equilibrium temperature | 1,089 K (816 °C) |
| Stellar irradiation | 235.00× Earth |
| Earth Similarity Index | 0.16 |
| Distance from Earth | 2,376.1 light-years (728.5 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2016 |
Data: NASA Exoplanet Archive, last updated 2024-09-13. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-553 b
Is Kepler-553 b habitable?
No — Kepler-553 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-553 b?
Kepler-553 b is about 2,376 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 41,819,360 years to get there.
How big is Kepler-553 b compared to Earth?
Kepler-553 b has 4.74 times the radius of Earth and about 116 times its mass.
How long is a year on Kepler-553 b?
One orbit around Kepler-553 takes 4.0 Earth days — short enough that 91 of its years would fit into one Earth year.
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