The presence of water ice clouds has been detected on our gas giant planets like Jupiter, Saturn, Uranus and Neptune. But, water ice clouds had not been found on planets outside the solar system.
Called “failed stars,” brown dwarfs form with insufficient mass to fuse hydrogen into helium in their cores — a process that defines a star. But these objects aren’t planets either. Instead, brown dwarfs bridge the gap between stars and planets and have masses at least 14 but no more than 80 times that of Jupiter.
A brown dwarf is a celestial or an astronomical object having a size between a small star and a giant planet, like Jupiter. In other words, brown dwarfs are too large to be classified as planets and too small to be called a star.
A very strange object called WISE 0855−0714 lies just 7.2 light-years from the earth. Discovered by the Wide-field Infrared Survey Explorer (WISE), it is nominally one of those not-quite-planets-not-quite-stars known as a brown dwarf.