Kepler-177 b
Kepler-177 b is a puffy low-density planet orbiting Kepler-177 in the constellation Lyra. It lies about 4,682 light-years from Earth and was discovered in 2013 using the transit method.
How Big Is Kepler-177 b?
Kepler-177 b has a radius of 3.50 times that of Earth. Its mass is 5.8 times that of Earth, giving it a density of 0.75 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-177 b in the Habitable Zone?
The position of Kepler-177 b relative to the habitable zone of Kepler-177 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-177: 0.981–2.313 AU (conservative: 1.242–2.193 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 ›
Temperature on Kepler-177 b
Kepler-177 b receives 30.40 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on Kepler-177 b — one full orbit around Kepler-177 — lasts 36.9 Earth days, shorter than Mercury's 88-day year.
How Was Kepler-177 b Discovered?
Kepler-177 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-177 b?
Kepler-177 b is 4,681.8 light-years (1,435.4 parsecs) from Earth. Light arriving here tonight left the planet about 4,682 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 82,399,680 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-177 b scores 0.22, ranking #3,595 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-177
Kepler-177
- Surface temperature
- 5,732 K (Sun: 5,772 K)
- Mass
- 0.92 M☉
- Radius
- 1.32 R☉
The Kepler-177 Planetary System
Kepler-177 b is one of 2 known planets in the Kepler-177 system. Its siblings:
- Kepler-177 c (Cold Gas Giant)
Kepler-177 b — Complete Data
| Radius | 3.500 Earth radii (0.312 Jupiter radii) |
|---|---|
| Mass | 5.84 Earth masses (0.018 Jupiter masses) |
| Density | 0.75 g/cm³ (Earth: 5.51) |
| Orbital period | 36.86 days |
| Stellar irradiation | 30.40× Earth |
| Earth Similarity Index | 0.22 |
| Distance from Earth | 4,681.8 light-years (1,435.4 parsecs) |
| Constellation | Lyra |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2013 |
Data: NASA Exoplanet Archive, last updated 2021-05-28. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-177 b
Is Kepler-177 b habitable?
Kepler-177 b is not known to orbit within the habitable zone of Kepler-177, and as a puffy low-density planet it is an unlikely candidate for life as we know it.
How far away is Kepler-177 b?
Kepler-177 b is about 4,682 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 82,399,680 years to get there.
How big is Kepler-177 b compared to Earth?
Kepler-177 b has 3.50 times the radius of Earth and about 5.8 times its mass.
How long is a year on Kepler-177 b?
One orbit around Kepler-177 takes 36.9 Earth days.
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