August 25th, 2011

NASA Chris, smiling Chris 2009

Astro-Porn of the Day: "Y dwarfs" stars as cool as the human body

NASA's Wide-field Infrared Survey Explorer (WISE) has discovered stars that are as cool as 80°F. No, really! And the nearest ones discovered are only 9 light-years away. Here's an artist's rendition:


Click the photo for the full story.

From the NASA press release:

Astronomers hunted these dark orbs for more than a decade without success. When viewed with a visible-light telescope, they are nearly impossible to see. WISE's infrared vision allowed the telescope to finally spot the faint glow of a half dozen Y dwarfs relatively close to our sun, within a distance of about 40 light-years.

"WISE scanned the entire sky for these and other objects, and was able to spot their feeble light with its highly sensitive infrared vision," says Jon Morse, Astrophysics Division director at NASA Headquarters in Washington.

The Y stars are the coldest members of the brown dwarf family. Brown dwarfs are sometimes referred to as "failed" stars. They are too low in mass to fuse atoms at their cores and thus don't burn with the fires that keep stars like our sun shining steadily for billions of years. Instead, these objects cool and fade with time, until what little light they do emit is at infrared wavelengths. The atmospheres of brown dwarfs are similar to those of gas giant planets like Jupiter, but they are easier to observe because they are alone in space, away from the blinding light of a parent star.

So far, WISE data have revealed 100 new brown dwarfs. Of these, six are classified as cool Y's. One of the Y dwarfs, called WISE 1828+2650, is the record holder for the coldest brown dwarf with an estimated atmospheric temperature cooler than room temperature, or less than 80°F (25° C).
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Oh, and the first week of classes is about to wrap up. Should be a great semester, if a bit overworked... technically, I have nine (9) classes this semester, though only three are full-size courses. Yeah, I know.

Chris