Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Counting atoms that aren’t there, in stars that no longer exist

30.01.2004


Argonne researchers use specialized instrument



Researchers at the U.S. Department of Energy’s Argonne National Laboratory have reached for the stars – and seen what’s inside.

Argonne scientists, in collaboration with colleagues at the University of Chicago, Washington University and the Universita di Torino in Italy, examined stardust from a meteorite and found remnants of now-extinct technetium atoms made in stars long ago.


The stardust grains are tiny bits of stars that lived and died before the solar system formed. Each grain is many times smaller than the width of a human hair, and carries a chemical record of nuclear reactions in its parent star.

Famed scientist P.W. Merrill fifty years ago observed the signature of live technetium - an element that has no stable isotopes - in the starlight from certain types of stars, thereby proving the then-controversial theory that stars make atoms via a process called nucleosynthesis. The researchers’ discovery that their stardust grains once harbored live technetium brings the science of nucleosynthesis full circle.

"Finding traces of technetium decay products in stardust provides a very precise confirmation of the theories of how atoms are made inside stars," said Michael Savina, Argonne scientist and the lead author on the research, which is published today in Science. "The fact that we can both predict and measure very tiny effects in the chemistry of these grains gives us a lot of confidence in our models of how stars work."

Authors on the report, in addition to Savina, are Michael Pellin and C. Emil Tripa of Argonne, Andrew M. Davis and Roy S. Lewis of the University of Chicago, Sachiko Amari of Washington University in St. Louis, and Roberto Gallino of Universita di Torino in Italy. Funding was provided by the U.S. Department of Energy Office of Science, the University of Chicago, NASA, and the Italian FIRB Progetto Origine Astrofisica degli Elementi Pesanti Oltre il Ferro.

The work was made possible by a specialized instrument at Argonne called CHARISMA, the only instrument of its type in the world. "CHARISMA is designed to analyze very tiny samples – the kind where you can’t afford to waste atoms, because there are so few of them to work with," Savina said.

CHARISMA is presently being upgraded, with funding from the Department of Energy Office of Science and from NASA, in anticipation of samples from the Genesis mission to collect samples of the solar wind – single atoms and electrically charged particles from the sun – which scientists believe hasn’t changed since the sun was born.

The research group at Argonne will be among the scientists to analyze the samples in an effort to better understand how the planets formed. Current measurements of the sun’s composition are not precise enough to answer key questions about events in the early solar system. The researchers are also preparing to analyze samples from the Stardust mission, which recently captured dust grains from a comet’s tail and will bring them back to Earth in 2006.


The nation’s first national laboratory, Argonne National Laboratory conducts basic and applied scientific research across a wide spectrum of disciplines, ranging from high-energy physics to climatology and biotechnology. Argonne has worked with more than 600 companies and numerous federal agencies and other organizations to help advance America’s scientific leadership and prepare the nation for the future. The University of Chicago operates Argonne as part of the U.S. Department of Energy’s national laboratory system.

Catherine Foster | EurekAlert!
Further information:
http://www.anl.gov/

More articles from Physics and Astronomy:

nachricht Physicists from Hannover Predict Novel Light Molecules
26.02.2020 | Leibniz Universität Hannover

nachricht From China to the South Pole: Joining forces to solve the neutrino mass puzzle
25.02.2020 | Johannes Gutenberg-Universität Mainz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: High-pressure scientists in Bayreuth discover promising material for information technology

Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.

The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...

Im Focus: From China to the South Pole: Joining forces to solve the neutrino mass puzzle

Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics

Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...

Im Focus: Therapies without drugs

Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.

A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Scientists develop algorithm for researching evolution of species with WGD

26.02.2020 | Information Technology

MOF co-catalyst allows selectivity of branched aldehydes of up to 90%

26.02.2020 | Life Sciences

Structural framework for tumors also provides immune protection

26.02.2020 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>