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10 April 2014 11:44 am ,
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Tight budgets are forcing NASA to consider turning off one or more planetary science projects that have completed their...
Ebola is not a stranger to West Africa—an outbreak in the 1990s killed chimpanzees and sickened one researcher. But the...
In an as-yet-unpublished report, an international panel of geoscientists has concluded that a pair of deadly...
Tropical disease experts tried and failed before to eradicate yaws, a rare disfiguring disease of poor countries. Now,...
Since 2002, researchers have reported that agricultural communities in the hot and humid Pacific Coast of Central...
Balkan endemic kidney disease surfaced in the 1950s and for decades defied attempts to finger the cause. It occurred...
The Pyrenean ibex, an impressive mountain goat that lived in the central Pyrenees in Spain, went extinct in 2000. But a...
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Cold 'Star' No Hotter Than a Summer's Day
22 March 2011 12:55 pm
Stars are stars, and planets are planets, and never the twain shall meet, right? Not quite. Brown dwarfs—so-called failed stars that are too small to sustain the stable burning of hydrogen—fall somewhere in between stars and planets when it comes to mass and temperature. Now, researchers have found two brown dwarfs that are colder than any previously seen—so cold and so small that they are almost like giant planets. In a paper published 20 March in The Astrophysical Journal Letters, a team reports on a brown dwarf about 63 light-years away whose temperature is barely 300 kelvin. That's 200 K cooler than the previous record holder and about as warm as a bright summer day on Earth. In a second study, to be published in an upcoming issue of The Astrophysical Journal, researchers describe another very cold brown dwarf (shown here in an infrared telescope image), whose estimated temperature is about 370 Kelvin. The two objects could be the first examples of a proposed class of ultra-cool brown dwarfs known as the Y-class. And because they are almost as cold as "gas giant" planets—Jupiter is about 150 K—studying them could offer a better handle on what the atmospheres of alien worlds look like.
For more information about these discoveries, see the 18 March issue of Science.
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