Dark stars

[alokmohan]

Perhaps the first stars in the newborn universe did not shine, but instead were invisible "dark stars" 400 to 200,000 times wider than the sun and powered by the annihilation of mysterious dark matter, a University of Utah study concludes. <br /><br />The study calculated how the birth of the first stars almost 13 billion years ago might have been influenced by the presence of dark matter, the unseen, yet-unidentified stuff that scientists believe makes up most matter in the universe.<br /><br />The findings "drastically alter the current theoretical framework for the formation of the first stars," says study author and astrophysicist Paolo Gondolo, associate professor of physics at the University of Utah.<br /><br />It is conceivable that gigantic dark stars may exist today, and although they do not emit visible light, they could be detected because they should spew gamma rays, neutrinos and antimatter and be associated with clouds of cold, molecular hydrogen gas that normally wouldn't harbor such energetic particles, he adds.<br /><br />"Without detailed simulations, we cannot pinpoint the further evolution of dark stars," Gondolo says. "They could last months. They could last 600 million years. Or they could last billions of years and still be around. We have to search for them."<br /><br />Gondolo says some studies have considered the role of dark matter in the evolution of the early universe, but until now, not in the formation of the first stars.<br /><br />Scientists know dark matter exists because galaxies rotate faster than can be explained by the visible matter within them. Also, observations by satellites, balloons and telescopes have led to the estimate that all the visible matter represents only 4 percent of the universe, which also is made of 23 percent dark matter and 73 percent "dark energy," a yet-unknown force helping the universe expand, Gondolo says.<br /><br />Weakly interacting massive particles, or WIMPs, are among the main candidates for dark matter. Gondo

 

[themage]

This is good stuff, thank you Alokmohan!

 

[alokmohan]

Thakk you TheMage,In 17th century Laplace thoght of dark stars in another angle.I shall tell it later on.

 

[lukman]

If early stars were dark star, then the chance for a future telescope like james webb to see earlier time of universe will become impossible. AFAIK dark star is very much a theory, are there dark star at present time? can we harvest the antimatter it produces <img src="/images/icons/smile.gif" /> What happen if dark star collide with a normal star? or black hole. I assume there are also dark black hole? wew, ho w do you detect that <img src="/images/icons/tongue.gif" /> <div class="Discussion_UserSignature"> </div>

 

[themage]

Yet again, Wiki saves the day!<br /><br />http://en.wikipedia.org/wiki/Dark_star<br /><br />And for alokmohan, http://en.wikipedia.org/wiki/Pierre-Simon_Laplace#Black_holes<br /><br /><br />In general, a black hole and a dark star have similarities. Read up on the article lukman, its good stuff <img src="/images/icons/smile.gif" />.