Saturday, April 28, 2007

Dazzling Image Captures the Violent Birth of Stars




WASHINGTON (Reuters) -- A dazzlingly detailed image released by NASA scientists on Tuesday shows the chaotic conditions in which stars are born and die -- in this case in a huge nebula in another neighborhood of our Milky Way galaxy.
The image, made from a series of 48 shots taken by the orbiting Hubble Space Telescope in spring and summer of 2005, depicts star birth in a new level of detail.
It provides a view spanning a distance of 50 light years across of the Carina Nebula. A nebula is an immense cloud of hot interstellar gas and dust.
This messy and chaotic region includes at least a dozen brilliant stars estimated to be perhaps 50 to 100 times the mass of the sun, astronomers said.
One of them, called Eta Carinae, is in the final stages of its short life span, with two billowing lobes of gas and dust -- a harbinger of its future explosion as a large supernova.
"In short, it gives us a glimpse of the violent conditions that most stars are born in, where they are exposed to the relentless irradiation from their older siblings," astronomer Nathan Smith of the University of California at Berkeley, the lead investigator in this work, said by e-mail.
"There are several clues suggesting that our sun and planets were indeed born in a violent region something like this, along with some very hot and massive stars," Smith added. Our solar system was formed about 4.6 billion years ago.
The nebula is about 7,500 light years away from Earth in the constellation Carina in a neighboring spiral arm of our Milky Way galaxy. The Hubble image depicts a massive region, but it is only a small portion of the whole nebula, which spans 150 to 200 light years across, Smith said.
People can see the nebula with the naked eye from Earth's southern hemisphere, Smith said.
"What you are seeing in the image is hot ionized gas -- in this case, the colors represent oxygen, hydrogen and sulfur at different temperatures," Smith added.
The image was released to coincide with the 17th anniversary of launching Hubble into orbit to provide scientists with clear and deep views of the universe without the Earth's atmosphere getting in the way. It is one of the largest panoramic images ever taken by Hubble.
The future of Hubble is in doubt because the space shuttle program is winding down in the coming years and the telescope needs manned maintenance missions to continue operations.
The image was released by NASA's Space Telescope Science Institute in Baltimore.


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