It is not a star. The only celestial objects it bears any resemblance to are the Jovian planets. We call it a brown dwarf, which is a label astronomers use to classify objects intermediate between planets and stars. The distinction between planets and brown dwarfs is a tricky issue and the subject of debate among astronomers. Distinguishing stars from brown dwarfs is agreed upon.
Stars shine because they play host to extremely energetic nuclear fusion reactions in their cores.
Brown dwarfs on the other hand are too small to produce the temperatures and pressures necessary to sustain these reactions in their cores. As a result they have no vast internal energy source. The only reason they do radiate is because they are heated up during the formation process through the conversion of the gravitational potential energy of a large interstellar gas cloud into heat in the small, condensed version of that cloud after it collapses. There is a piece of metal sticking out into the center of the image. This is present to remove most of the light of the primary star, which would otherwise drown out the signal from the brown dwarf.