EAST LANSING, Mich. – Gold and other precious metals have been discovered,
but they won’t be mined anytime soon.
Michigan State University astronomer Timothy C. Beers is part of a team
of scientists that has discovered gold in an ancient star in the halo
of the Milky Way, the first time the existence of the element has been
discovered in a star other than Earth’s own sun.
In addition to the uniqueness of the finding of gold, the discovery
of other elements, including radioactive elements, in this star also helps
astronomers pinpoint the age of the star and provides clues to the age
of our galaxy and the universe.
Using the Hubble Space Telescope and the Keck Telescope in Hawaii, Beers
and colleagues were able to detect and measure the abundances of gold,
silver, platinum and the radioactive element thorium in a star known as
BD+17 3248, located some 2,500 light years from Earth. There is even a
hint of the presence of the radioactive element uranium, Beers said.
“This is the first time gold has been detected in any other star,” said
Beers, a professor in MSU’s Department of Physics and Astronomy.
“While every star probably has similar amounts of gold, this is the first
time its existence has been confirmed,” said Christopher Sneden, a member
of the research team from the University of Texas. “It also helps provide
a few clues as to how the elements came into being.”
“In a manner of speaking, the gold in BD+17 3248 is representative of
the first gold to have been made in the galaxy,” Beers said. “This star
was likely to have formed within the first half-million years after the
beginning of the galaxy – some 15 billion years ago – while our sun only
formed some five billion years ago.”
Beers said the discovery is significant because elements such as gold
and platinum could not have been produced internally within the star.
Rather, the elements that are presently observed in the outer atmosphere
of this star were created in the early galaxy by the explosion of a much
more massive star, a supernova, that forged these heavy elements via a
process known as rapid neutron capture.
Beers and a group of international collaborators have been searching
the halo of the galaxy for such ancient stars for more than two decades,
and now the payoff for that long-term effort is coming to pass.
“The discovery of gold and other interesting elements in this star reaffirms
our picture that the story of the creation of the elements is written
in the atmospheres of these ancient stars,” Beers said. “The most exciting
thing is that we are finally in a position to begin reading, and understanding,
this intriguing history.”
The researchers estimated that at today’s rates, the amount of gold in
this star would be worth 7 billion trillion dollars.
The discovery was presented at a meeting of the American Astronomical
Society in Washington, D.C.
Other members of the research team include the team leader, John Cowan
of the University of Oklahoma; Inese Ivans of the University of Texas;
Scott Burles of the Massachusetts Institute of Technology; James Truran
of the University of Chicago; James Lawler of the University of Wisconsin;
Francesca Primas of the European Southern Observatory, Germany; George
Fuller of the University of California at San Diego; and Karl-Ludwig Kratz
and Bernd Pfeiffer of the University of Mainz, Germany.
The research was funded by the National Aeronautical and Space Administration,
the National Science Foundation, the U.S. Department of Energy, and Germany’s
Federal Ministry for Education and Research.
