Kepler-1876 b
Kepler-1876 b is a terrestrial planet orbiting Kepler-1876 in the constellation Cygnus. It lies about 848 light-years from Earth and was discovered in 2021 using the transit method.
How Big Is Kepler-1876 b?
Kepler-1876 b has a radius of 0.85 times that of Earth. Its mass is 2.4 times that of Earth, giving it a density of 19.00 g/cm³ — comparable to rocky planets like Earth (5.51 g/cm³).
Is Kepler-1876 b in the Habitable Zone?
Kepler-1876 b orbits inside the inner edge of the habitable zone of Kepler-1876. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-1876: 1.213–2.835 AU (conservative: 1.536–2.688 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on Kepler-1876 b
The equilibrium temperature of Kepler-1876 b is about 1,299 K (1,026 °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 475 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on Kepler-1876 b — one full orbit around Kepler-1876 — lasts 6.99 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.076 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.10).
How Was Kepler-1876 b Discovered?
Kepler-1876 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-1876 b?
Kepler-1876 b is 847.8 light-years (259.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1179. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 14,921,280 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-1876 b scores 0.29, ranking #1,626 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-1876
Kepler-1876
- Surface temperature
- 6,104 K (Sun: 5,772 K)
- Mass
- 1.19 M☉
- Radius
- 1.48 R☉
- Age
- 4.4 billion years (Sun: 4.6)
Planetary System
Kepler-1876 b is the only planet known to orbit Kepler-1876 so far.
Kepler-1876 b — Complete Data
| Radius | 0.853 Earth radii (0.076 Jupiter radii) |
|---|---|
| Mass | 2.40 Earth masses (0.008 Jupiter masses) |
| Density | 19.00 g/cm³ (Earth: 5.51) |
| Orbital period | 6.99 days |
| Orbital distance | 0.076 AU |
| Eccentricity | 0.098 |
| Equilibrium temperature | 1,299 K (1,026 °C) |
| Stellar irradiation | 475.00× Earth |
| Earth Similarity Index | 0.29 |
| Distance from Earth | 847.8 light-years (259.9 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2021 |
Data: NASA Exoplanet Archive, last updated 2023-04-17. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-1876 b
Is Kepler-1876 b habitable?
No — Kepler-1876 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-1876 b?
Kepler-1876 b is about 848 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 14,921,280 years to get there.
How big is Kepler-1876 b compared to Earth?
Kepler-1876 b has 0.85 times the radius of Earth and about 2.4 times its mass.
How long is a year on Kepler-1876 b?
One orbit around Kepler-1876 takes 7.0 Earth days — short enough that 52 of its years would fit into one Earth year.
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