GJ 1214 b

GJ 1214 b / Enaiposha
Size comparison of Enaiposha with Earth (left) and Neptune (right). The actual color of Enaiposha is not yet known.
Discovery[1]
Discovered byDavid Charbonneau, et al.
Discovery siteFred Lawrence Whipple Observatory
Discovery dateDecember 16, 2009
Transit (MEarth Project)
Designations
Enaiposha[2], Gliese 1214 b
Orbital characteristics[3]
0.01490±0.00026 AU
Eccentricity<0.063
1.580404571(42) d[4]
Inclination88.7°±0.1°
Semi-amplitude14.36±0.53 m/s
StarOrkaria/GJ 1214
Physical characteristics
2.742+0.050
−0.053 R🜨[3]
Mass8.17±0.43 M🜨[3]
Mean density
2.20+0.17
−0.16 g/cm3[3]
10.65+0.71
−0.67 m/s2[3] (1.09 g)
19.31+0.53
−0.54 km/s[3]
Albedo0.51±0.06 (Bond)[5]
Temperature553±9 K (280 °C; 536 °F, dayside)[5]
437±19 K (164 °C; 327 °F, nightside)[5]

GJ 1214 b (sometimes Gliese 1214 b,[6] also named Enaiposha since 2023[2]) is an exoplanet that orbits the star GJ 1214, and was discovered in December 2009. Its parent star is 48 light-years from the Sun, in the constellation Ophiuchus. As of 2017, GJ 1214 b is the most likely known candidate for being an ocean planet.[1][7] For that reason, scientists often call the planet a "waterworld".[8] 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, with the planet being more likely to host a thick gaseous envelope consisting of hydrogen, helium, water and other volatile species such as methane or carbon dioxide.[9]

It is a super-Earth, meaning it is larger than Earth but is significantly smaller (in mass and radius) than the gas giants of the Solar System. After CoRoT-7b, it was the second super-Earth to have both its mass and radius measured[1] and is the first of a new class of planets with small size and relatively low density.[10] GJ 1214 b is also significant because its parent star is relatively near the Sun and because it transits that parent star, which allows the planet's atmosphere to be studied using spectroscopic methods.[1]

In December 2013, NASA reported that clouds may have been detected in the atmosphere of GJ 1214 b.[11][12][13][14]

  1. ^ a b c d Cite error: The named reference Charbonneau2009 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference NEW2022 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Cloutier2021 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Kokori2023 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Kempton2023 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference OEC-GJ1214b was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference planetmodels2 was invoked but never defined (see the help page).
  8. ^ "10 real planets that are stranger than science fiction". iflscience.com. 3 June 2015. Retrieved 2015-06-13.
  9. ^ Cite error: The named reference Nixon2024 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference arxiv0912 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference NASA-20131231 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference NAT-20140101a was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference NAT-20140101b was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference NAT-20140101c was invoked but never defined (see the help page).