Wednesday, December 20, 2006

First Stars in the universe?

Ok..so not directly science & religion, but this still touches on the issue of origins (and its really cool!). Using Spitzer Space Telescope (it works in the infrared), astronomers have found possible signs of first stars in the universe that lived about 13 billion years ago. Why do astronomers care about this? Almost all elements other than hydrogen and helium (these were produced in the Big Bang) have been processed inside stars or in the explosions of dying stars. But stars are great at recycling - the next generation of stars is born out of gaseous material ejected by dying stars. Thus all the stars that we see contain at least some recycled material - observed in the form of elements heavier than hydrogen & helium (our Sun is a third generation star). But there has to be a first generation of stars made up purely of hydrogen and NO processed elements.

These stars, for various reasons, are expected to be much bigger than the stars we see today. These are also expected to live a very short life time (perhaps less than a million years) thus quickly providing processed material for the next generation of stars. The Spitzer observations have either found light from these first generation stars, each about 1000 times as massive as our Sun, or this light is from some early black holes. This is one of those rare instances where the possibility of black holes is less exciting than the discovery of stars. You can read the full story here:

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