KOI-55 c
The parameters of this planet are disputed or ambiguous in the scientific literature.
KOI-55 c is a terrestrial planet orbiting the B star KOI-55 in the constellation Cygnus. It lies about 4,015 light-years from Earth and was discovered in 2011 using the orbital brightness modulation method.
How Big Is KOI-55 c?
KOI-55 c has a radius of 0.87 times that of Earth. Its mass is 0.66 times that of Earth.
Is KOI-55 c in the Habitable Zone?
The position of KOI-55 c relative to the habitable zone of KOI-55 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on KOI-55 c — one full orbit around KOI-55 — lasts just 8.2 hours, shorter than Mercury's 88-day year. It orbits at an average distance of 0.008 AU — closer to its star than Mercury is to the Sun.
How Was KOI-55 c Discovered?
KOI-55 c was discovered in 2011 using the orbital brightness modulation method, with observations from Kepler.
Orbital brightness modulation detects a planet from minute periodic changes in the combined light of the system as the planet orbits — including light reflected by the planet and relativistic effects it induces on the star.
How Far Away Is KOI-55 c?
KOI-55 c is 4,015.0 light-years (1,231.0 parsecs) from Earth. Light arriving here tonight left the planet about 4,015 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 70,664,000 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. KOI-55 c scores 0.29, ranking #1,791 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: KOI-55
KOI-55
- Spectral type
- B
- Surface temperature
- 27,730 K (Sun: 5,772 K)
- Mass
- 0.50 M☉
- Radius
- 0.20 R☉
- Luminosity
- 22.9087 L☉
The KOI-55 Planetary System
KOI-55 c is one of 2 known planets in the KOI-55 system. Its siblings:
- KOI-55 b (Terrestrial)
KOI-55 c — Complete Data
| Radius | 0.867 Earth radii (0.077 Jupiter radii) |
|---|---|
| Mass | 0.66 Earth masses (0.002 Jupiter masses) |
| Orbital period | 0.34 days |
| Orbital distance | 0.008 AU |
| Earth Similarity Index | 0.29 |
| Distance from Earth | 4,015.0 light-years (1,231.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Orbital Brightness Modulation |
| Discovery facility | Kepler |
| Discovery year | 2011 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About KOI-55 c
Is KOI-55 c habitable?
KOI-55 c is not known to orbit within the habitable zone of KOI-55, and as a terrestrial planet it is an unlikely candidate for life as we know it.
How far away is KOI-55 c?
KOI-55 c is about 4,015 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 70,664,000 years to get there.
How big is KOI-55 c compared to Earth?
KOI-55 c has 0.87 times the radius of Earth and about 0.66 times its mass.
How long is a year on KOI-55 c?
One orbit around KOI-55 takes 0.3 Earth days — short enough that 1,065 of its years would fit into one Earth year.
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