A super-Neptune is basically a planet that is more massive than the planet Neptune, and are generally around 5–7 times as large as Earth. One of these massive planets was discovered by astronomers using the Italian Telescopio Nazionale Galileo and the High Resolution Echelle Spectrometer on the Keck Telescope in the Gliese 15 binary system, which is located 11.6 light-years from Earth. Read more for a video and additional information.
This planet is located in the Gliese 15 binary system where planets move around two red dwarf stars. There have been relatively few discoveries of super-Neptunes, but other known examples include Kepler-101b, HAT-P-11b, and K2-33b.
With its period of 7,600 days (20.8 years), Gliese 15Ac is the longest-period sub-Jovian planet detected up to date with the radial velocity method. With the confirmed presence of two widely spaced planetary-mass companions, Gliese 15A is now the multi-planet system closest to our sun,” said Dr. Pinamonti.