NASA (Exoplanet Catalog artwork)Gliese 1214 b
also named EnaiposhaThe archetypal sub-Neptune, wrapped in haze that defeated Hubble
Overview
GJ 1214 b is an exoplanet with a very high temperature that orbits the star GJ 1214, discovered in December 2009. Its parent star is 48 light-years (15 pc) from the Sun, in the constellation Ophiuchus. At the time of its discovery, GJ 1214 b was the most likely known candidate for being an ocean planet. For that reason, scientists at that time often called the planet a "waterworld". However, a recent study of the planet's internal structure informed by observations taken with the James Webb Space Telescope suggests that a "waterworld" composition is implausible and the planet is more likely to host a thick gaseous envelope consisting of hydrogen, helium, water and other volatile chemicals such as methane or carbon dioxide.
Source: Wikipedia
NASA: GJ 1214 b is a Neptune-like exoplanet that orbits a M-type star. Its mass is 8.41 Earths, it takes 1.6 days to complete one orbit of its star, and is 0.01505 AU from its star. Its discovery was announced in 2009.
Why it matters
- Discovered in 2009 by the small MEarth telescopes; the first sub-Neptune with a studied atmosphere.
- Hubble saw a featureless spectrum, implying thick clouds or haze.
- JWST's 2023 heat map showed a highly reflective, probably water- or metal-rich atmosphere.
NASA puts it this way: “GJ 1214 b is a Neptune-like exoplanet that orbits an M-type star. Its mass is 8.17 Earths, it takes 1.6 days to complete one orbit of its star, and is 0.0149 AU from its star. Its discovery was announced in 2009.”
Discovery & system
- Discovered
- 2009 · Transit · MEarth Project
- Discovery paper
- Charbonneau et al. 2009
- Discoverers
- David Charbonneau
- Host star
- GJ 1214 · M4 V · 3,101 K · 0.18 M☉
- System
- 1 known planet
The system
| World | Period | Distance | Radius | Mass | Temp. |
|---|---|---|---|---|---|
| GJ 1214 b | 1.58 d | 0.015 AU | 2.73 R⊕ | 8.41 M⊕ | 567 K |
By the numbers
- Radius
- 2.73 R⊕17,412 km
- Mass
- 8.41 M⊕50.23 ×10²⁴ kg
- Orbital period
- 1.58 d0 yr
- Distance from star
- 0.015 AU2.25 million km
- Eccentricity
- 0.006nearly circular
- Equilibrium temp.
- 567 K294 °C
- Starlight received
- 17 × Earth
- Distance from Earth
- 47.8 ly14.6 pc
- Density
- 2.26 g/cm³0.41 × 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.