Scientists Find Possible Dawn-Of-Time Star

Science - Reuters ^ | 10/30/2002

[Junior]

LONDON (Reuters) - A group of scientists has discovered a distant star that could date back to the beginning of the Universe.

The giant star, HE0107-5240, is a galactic rarity because it is virtually metal-free unlike the other, more modern known stars, they wrote in the science journal Nature.

"These old stars provide crucial clues to the star formation history and the synthesis of chemical elements in the early Universe," they said.

"If totally metal-free stars could be found, this would allow the direct study of the pristine gas from the Big Bang," they added.

The existence of stars with zero or very low metal content has been hypothesized for decades, but none has ever been found before -- throwing the theory into doubt.

At the dawn of time these stars contained most of the elements in the Universe.

But quite early in its history these nuclear furnaces began to convert the lighter elements into heavier ones like carbon, phosphorous and lead -- collectively known as metals.

In theory, therefore, there were once large numbers of the low or zero-metal stars some of which should still exist but which -- until the discovery of HE0107-5240 -- had never been found.

"This discovery suggests that (metal-free) stars could still exist -- that is, that the first generation of stars also contained long-lived low-mass objects," the scientists said.

"The previous failure to find them may be an observational selection effect," they added.

The scientists are from Sweden, Germany, Australia, the United States and Brazil.

[inquest]

And since the object under study would have to be low-mass (otherwise it wouldn't still be around), we can then assume that its barriers formed pretty quickly?

[ThinkPlease]

And since the object under study would have to be low-mass (otherwise it wouldn't still be around), we can then assume that its barriers formed pretty quickly?

A Wolf-Rayet star is believed to be an extremely high mass star due to it's place on the Hertzprung-Russell diagram (extreme high left), and is actually believed to not have much of a convective barrier, unlike lowermass stars. Because of the extreme luminosity of the star, the radiation pressure caused by the sheer volume of photons being emitted is believed to prevent much of a convective zone from ever being formed. This is a bright, massive star. If one of these stars were as close as Deneb or Betelgeuse, it's brightness would rival the brightest stars in the sky. Luckily for us (because they are prime supernova candidates), the nearest one is over a 3000 lightyears away.