Scientists Describe Formation of First Stars

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.

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.