Brr! Hubble sees coldest spot in cosmos
By Richard Stenger
CNN
Friday, February 21, 2003 Posted: 12:15 PM EST (1715 GMT)
The Boomerang Nebula is 5,000 light-years away in the constellation Centaurus.
(CNN) -- The coldest known object in the universe comes into sharp focus in a newly released image from the Hubble Space Telescope.
The Boomerang Nebula, a shell of glowing gas around a fading star, hovers just above absolute zero, the lowest possible temperature.
At minus 272 degrees Celsius, it is even chillier than background radiation from the Big Bang, which is a "balmy" minus 270 degrees Celsius.
Absolute zero is minus 273 degrees Celsius (minus 459 degrees Fahrenheit), a temperature at which point the movement of atomic particles comes nearly to a standstill.
The Boomerang Nebula received its peculiar name in 1980 because early ground-based telescope pictures of the oddity were not in sharp focus.
"Unable to see the detail that only Hubble can reveal, the astronomers saw merely a slight asymmetry in the nebula's lobes, suggesting a curved shape like a boomerang," Hubble researchers said in a statement.
The Hubble image, released Thursday, suggests the name Bow Tie Nebula might be more appropriate for the wispy structure of arcs and filaments.
Often the lobes of nebulae look like bubbles blown in gas, but this particular one is so young that it may not have had time to form them, astronomers theorize.
The Boomerang Nebula could be colder than other expanding nebulae because its central star loses its mass about 100 times faster than similar dying celestial bodies, according to NASA's Raghvendra Sahai, one of the first Boomerang researchers.
The gaseous winds from the central star blow at speeds greater than 300,000 mph (500,000 km/h), bringing about a rapid expansion that supercools the gas like a "cosmic refrigerator," Sahai said in a previous statement.
The bizarre and colorful shapes of planetary nebulae have nothing to with planets. They are so named because astronomers using simple telescopes centuries ago mistook the fuzzy figures for planets.
cnn.com |
