Kepler-1873 b
Kepler-1873 b is a super-Earth orbiting Kepler-1873 in the constellation Cygnus. It lies about 2,678 light-years from Earth and was discovered in 2021 using the transit method.
How Big Is Kepler-1873 b?
Kepler-1873 b has a radius of 1.63 times that of Earth.
Is Kepler-1873 b in the Habitable Zone?
The position of Kepler-1873 b relative to the habitable zone of Kepler-1873 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-1873: 0.489–1.176 AU (conservative: 0.620–1.115 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 ›
Orbit and Year Length
A year on Kepler-1873 b — one full orbit around Kepler-1873 — lasts just 13.4 hours, shorter than Mercury's 88-day year.
How Was Kepler-1873 b Discovered?
Kepler-1873 b was discovered in 2021 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-1873 b?
Kepler-1873 b is 2,677.6 light-years (821.0 parsecs) from Earth. Light arriving here tonight left the planet about 2,678 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 47,125,760 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-1873 b scores 0.27, ranking #2,472 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-1873
Kepler-1873
- Surface temperature
- 5,151 K (Sun: 5,772 K)
- Mass
- 0.90 M☉
- Radius
- 0.79 R☉
Planetary System
Kepler-1873 b is the only planet known to orbit Kepler-1873 so far.
Kepler-1873 b — Complete Data
| Radius | 1.626 Earth radii (0.145 Jupiter radii) |
|---|---|
| Orbital period | 0.56 days |
| Earth Similarity Index | 0.27 |
| Distance from Earth | 2,677.6 light-years (821.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2021 |
Data: NASA Exoplanet Archive, last updated 2021-12-05. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-1873 b
Is Kepler-1873 b habitable?
Kepler-1873 b is not known to orbit within the habitable zone of Kepler-1873, and as a super-Earth it is an unlikely candidate for life as we know it.
How far away is Kepler-1873 b?
Kepler-1873 b is about 2,678 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 47,125,760 years to get there.
How big is Kepler-1873 b compared to Earth?
Kepler-1873 b has 1.63 times the radius of Earth.
How long is a year on Kepler-1873 b?
One orbit around Kepler-1873 takes 0.6 Earth days — short enough that 654 of its years would fit into one Earth year.
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