The term "failed star" refers to a celestial object that was initially formed as a star but did not maintain enough mass or gravitational force to sustain nuclear fusion in its core. Full definition
By observing a brown dwarf 20 light - years away, researchers have found another feature that makes these so - called failed stars more like supersized planets — they host powerful aurorae near their magnetic poles. (astronomynow.com)
Brown dwarfs can be thought of as failed stars because they are too small to fuse chemical elements in their cores. (sciencedaily.com)
With the increases in technology and astronomical know - how since then, a bounty of new objects may await discovery by WISE, from distant galaxies whose optical light is dwarfed by their infrared output to failed stars known as brown dwarfs, some of which may be closer to Earth than the star Proxima Centauri, the sun's nearest known neighbor. (scientificamerican.com)