Washington
31 July 2008
An international team of scientists has devised a computer model
detailing how the first stars were born. VOA's Jessica Berman reports
the researchers say knowing how stars were created is crucial to
understanding planets and other space objects.
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| Galaxy cluster |
Japanese and U.S.
space scientists say the first stars, which they call protostars, were
made from small grains of dust and gases unleashed by the Big Bang, the
massive explosion they say created the universe 13 billion years ago.
In
a study published in this week's journal Science, Japanese
astrophysicist Naoki Yoshida and colleagues unveil a sophisticated
computer model describing what they think happened in the period
between the Big Bang and the formation of universe as scientists know
it today.
"Our simulation offers a very clear picture of how the
first stars are formed in our universe. And also it offers a story
about the origin of light and of heavy elements in the universe," he
said.
According to the model, the wispy protostars were made
when helium, hydrogen and dust drew together by the mysterious dark
matter after the Big Bang, gravity and other conditions that existed in
the primordial universe.
The scientists say the first stars were at least 100 times larger than our Sun, but they were one tenth the mass.
Based
on their calculations, the scientists think protostars burned very
bright in small clusters of the universe for a billion years before
dying, and almost certainly depositing heavy elements, such as iron and
carbon, into the universe.
Lars Hernquist is a professor of
astronomy at Harvard University in Massachusetts and co-author of the
study. Hernquist says the material was the basis for future star
formation. "And so we need to understand what the detailed properties
of these stars were so that we can understand what happens when
subsequent stars form and they aggregate together to form the first
galaxies."
The scientists say it is not possible to see
protostars through a telescope, although it may still be possible to
view a second-generation star.
The astronomers say they are
working on an even more sophisticated computer simulation model of the
universe, one that might even allow them to peer into the future.