Kepler-11 g

Kepler-11g is an exoplanet discovered in the orbit of the sunlike star Kepler-11 by the Kepler space telescope, a NASA satellite tasked with searching for terrestrial planets. Kepler-11g is the outermost of the star's six planets. The planet orbits at a distance of nearly half the mean distance between Earth and the Sun. It completes an orbit every 118 days, placing it much further from its star than the system's inner five planets. Its estimated radius is a little over three times that of Earth, i.e. comparable to Neptune's size. Kepler-11g's distance from the inner planets made its confirmation more difficult than that of the inner planets, as scientists had to work to exhaustively disprove all reasonable alternatives before Kepler-11g could be confirmed. The planet's discovery, along with that of the other Kepler-11 planets, was announced on February 2, 2011. According to NASA, the Kepler-11 planets form the flattest and most compact system yet discovered.

==Name and discovery== Kepler-11 was originally called KOI-157 when NASA's Kepler spacecraft flagged the star for possible transit events, which exhibit tiny and roughly periodic decreases in the star's brightness are measured as it passes in front of its star as seen from Earth. Kepler-11's name is incorporated into Kepler-11g's name because it is the host star. As Kepler-11g and its five sister planets were discovered and announced at the same time, its planets were sorted alphabetically by distance from the host star, starting with the letter b. Because Kepler-11g was the furthest of the six, it was given the designation "g."