ScienceShot: Astronomers Find 14 of the Galaxy's Coldest Suns

The Milky Way could be filled with hundreds of billions of stars so tiny and faint we can't see them in optical light. That's the conclusion of a new study, which has found 14 of the coldest brown dwarfs yet. Brown dwarfs are stars that formed with too little mass to ignite their nuclear furnaces, so they can't shine or stay hot. Astronomers using the Spitzer Space Telescope, which can see in infrared light, picked out the objects (inset) among their bigger, visible cousins. Based on the findings, the team reports this month in the Astronomical Journal, that brown dwarfs could outnumber the conventional stars in the galaxy, as this simulated image shows. In fact, they could be the most plentiful objects in the sun's galactic neighborhood, with one or more of them sitting closer than Proxima Centauri, the nearest star to the sun. And a brown dwarf could even be orbiting the sun as a hidden companion--an as-yet-undiscovered body that some astronomers have named Tyche.

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