Until recently, astronomers believed that the first stars were ultra-giants which blew themselves apart long ago. Now a new model of the universe suggests that some the first stars of the universe may still be burning today.
Although space appears to be full of vast stretches of nothing, between thirteen and fourteen billion years ago it was a much denser place. The infant universe was thick with matter, and gravitation caused that matter to condense very quickly. The stars that formed were giants, much larger than our current sun. Their mass caused them to crush their own centers, creating nuclear fusion. This nuclear fusion created enough energy to prop up the outer layers of the star. Over time, larger and larger elements were fused, and the stars grew low on fuel. When no more material could be fused, the outer layers of the stars collapsed inwards, triggering one last release of energy that blew them apart. The only things left were the heavy elements that formed the planets and life on them.
It was only later, when the universe got less dense and matter was hard to come by, when smaller stars were born. Many of these small stars burned longer, since they didn't eat through their supply of fuel so voraciously. The earth's warm, mellow sun is an example of a medium sized, enduring star.
But scientists at the University of Heidelberg believe that early stars might still be shining. It was thought that early stars developed alone, each in their own enormous gas cloud. The Heidelbergers believe that, instead of this solitary life, these proto-stars grew in a nursery of several stars at a time. When stars are close together, they move around quite quickly. Each star's gravity pulls on the other stars; so they circle each other and kick each other one way or another. One of these kicks could have sent an early star out of the cloud of gas. Indeed, many modern stars are ejected from their nebulae in just that way.
If the star were thrown out when it was already big and heavy, it would burn away like all the rest. Since stars can be ejected at any phase, though, at least some would have been thrown clear of the gas cloud when they were still small enough to burn slow. These scientists believe that those stars may still be out there, watching the entire universe expand around them while they smoulder. We might even be seeing light from the first star that ever ignited.
Via Science News.