NASA (Exoplanet Catalog artwork)Kepler-78b
An Earth-sized lava world with an 8.5-hour year
Overview
Kepler-78b is an exoplanet orbiting around the star Kepler-78. At the time of its discovery, it was the exoplanet most similar to Earth in terms of mass, radius, and mean density.
Source: Wikipedia
NASA: Kepler-78 b is a super Earth exoplanet that orbits a K-type star. Its mass is 1.68 Earths, it takes 0.4 days to complete one orbit of its star, and is 0.00901 AU from its star. Its discovery was announced in 2013.
Why it matters
- Discovered in 2013; the first Earth-sized exoplanet with both mass and radius measured, and an Earth-like density.
- Orbits 40 times closer to its star than Mercury, with a surface hot enough to melt rock.
- Should not exist where it is — it is too close for in-situ formation and too far from being destroyed.
NASA puts it this way: “Kepler-78 b is a super Earth exoplanet that orbits a K-type star. Its mass is 1.68 Earths, it takes 0.4 days to complete one orbit of its star, and is 0.00901 AU from its star. Its discovery was announced in 2013.”
Discovery & system
- Discovered
- 2013 · Transit · Kepler
- Discovery paper
- Sanchis-Ojeda et al. 2013
- Discoverers
- Kepler Space Telescope
- Host star
- Kepler-78 · G · 5,058 K · 0.78 M☉
- System
- 1 known planet, 2 stars
The system
| World | Period | Distance | Radius | Mass | Temp. |
|---|---|---|---|---|---|
| Kepler-78 b | 8.5 h | 0.009 AU | 1.2 R⊕ | 1.68 M⊕ | 2,223 K |
By the numbers
- Radius
- 1.2 R⊕7,652 km
- Mass
- 1.68 M⊕10.03 ×10²⁴ kg
- Orbital period
- 8.5 h
- Distance from star
- 0.009 AU1.35 million km
- Eccentricity
- 0nearly circular
- Equilibrium temp.
- 2,223 K1,950 °C
- Starlight received
- 4,070 × Earth
- Distance from Earth
- 406 ly124.4 pc
- Density
- 5.33 g/cm³0.97 × Earth
Sources
Image: NASA (Exoplanet Catalog artwork) · NASA media: generally free of copyright · image page
Text: Wikipedia (CC BY-SA 4.0). Taglines and highlights are editorial.