WISE, a NASA satellite dedicated to scanning the entire sky in infrared light, found the celestial object, which belongs to a class called brown dwarfs that have too little mass to become full-blown stars.
IPAC-Caltech / NASA
That green dot in the middle of this image might look like an emerald amid glittering diamonds, but it's actually a dim star belonging to a class called brown dwarfs. This object, named WISEPC J045853.90+643451.9 after its location in the sky, is the first ultra-cool brown dwarf discovered by NASA's WISE satellite.
She said the newly discovered brown dwarf actually appears as a green object because its methane gasses absorb the blue, infrared light.
NASA scientists are excited about the find.
"They're a great test of our understanding of atmospheric physics of planets, since they don't have solid surfaces, and there's no big, bright sun to get in the way," said Michael Cushing, a fellow at the laboratory.
Mainzer said the star, now dubbed WISEPC J045853.90+643451.9, is an especially stinky find. Made up mostly of methane, hydrogen sulfide and ammonia, the brown dwarf may smell something like rotten eggs to the human nose.
"If you could bottle up a gallon of this object's atmosphere and bring it back to Earth, smelling it wouldn't kill you, but it would stink pretty badly -- like rotten eggs with a hint of ammonia," she said.
With an atmosphere of about 620 degrees Fahrenheit, or 327 degrees Celsius, it's also one of the coldest stars on record.
NASA scientists say they expect WISE to discover many more brown dwarfs in the near future. The satellite has been orbiting the Earth 15 times a day.