GJ 1214
Encyclopedia
GJ 1214 is a dim M4.5 red dwarf
in the constellation Ophiuchus
with an apparent magnitude
of 14.7. It is located at a distance of approximately 40 light years from Earth
. It is about one-fifth as large as the Sun
with a surface temperature estimated to be 3000 K. Its luminosity is only 0.3% that of the Sun.
The estimate for the stellar radius is 15% larger than predicted by theoretical models.
, GJ 1214 b, potentially composed largely of water and having the mass and diameter of a super-Earth
.
Discovered by the MEarth project and investigated further by the HARPS spectrograph on ESO
’s 3.6-metre telescope at La Silla, GJ1214b is the second super-Earth exoplanet for which astronomers have determined the mass and radius, giving vital clues about its structure. It is also the first super-Earth around which an atmosphere has been found.
Red dwarf
According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....
in the constellation Ophiuchus
Ophiuchus
Ophiuchus is a large constellation located around the celestial equator. Its name is from the Greek "serpent-bearer", and it is commonly represented as a man grasping the snake that is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century...
with an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
of 14.7. It is located at a distance of approximately 40 light years from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. It is about one-fifth as large as the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
with a surface temperature estimated to be 3000 K. Its luminosity is only 0.3% that of the Sun.
The estimate for the stellar radius is 15% larger than predicted by theoretical models.
Planetary system
In mid-December 2009, a team of Harvard-Smithsonian astronomers announced the discovery of a companion extrasolar planetExtrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
, GJ 1214 b, potentially composed largely of water and having the mass and diameter of a super-Earth
Super-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below the mass of the Solar System's gas giants. The term super-Earth refers only to the mass of the planet, and does not imply anything about the surface conditions or habitability...
.
Discovered by the MEarth project and investigated further by the HARPS spectrograph on ESO
European Southern Observatory
The European Southern Observatory is an intergovernmental research organisation for astronomy, supported by fifteen countries...
’s 3.6-metre telescope at La Silla, GJ1214b is the second super-Earth exoplanet for which astronomers have determined the mass and radius, giving vital clues about its structure. It is also the first super-Earth around which an atmosphere has been found.