(It's not a star, it's not a planet) Meet the brown dwarf
[Above: Artist’s impression of a brown dwarf based on data from Nasa’s Hubble and Spitzer space telescopes. Image: Nasa]
IN A UNIVERSE POPULATED by the bizarre and unusual it takes a special talent to be singled out as a space oddity but if there is one celestial object that deserves this moniker it is the lowly brown dwarf.
Stuck in a strange no-man’s land between stars and planets, and accused of being dull, smelly (their atmosphere’s rich with eggy hydrogen sulphide and uriney ammonia), underachieving loners; brown dwarfs are one of the Universe’s most maligned objects – a sort of cosmic hobo if you will.
Formed from the collapse of clouds of gas and dust, brown dwarfs start their lives full of the promise of stardom. But they never manage to gather enough mass to ignite full-blooded hydrogen fusion in their cores and, instead of becoming blazing stars surrounded by supplicant planets, they resemble enormous Jupiter-like planets – doomed to billions of years of cold obscurity.