Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Weizmann Institute scientists observe the largest exploding star yet seen

23.03.2009
Scientists from the Weizmann Institute of Science and San Diego State University managed to observe a super-sized supernova explosion from start to finish, including the black hole ending.

In the first observation if its kind, scientists at the Weizmann Institute of Science and San Diego State University were able to watch what happens when a star the size of 50 suns explodes. As they continued to track the spectacular event, they found that most of the star's mass collapsed in on itself, resulting in a large black hole.

While exploding stars - supernovae - have been viewed with everything from the naked eye to high-tech research satellites, no one had directly observed what happens when a really huge star blows up. Dr. Avishay Gal-Yam of the Weizmann Institute's Faculty of Physics and Prof. Douglas Leonard of San Diego State University recently located and calculated the mass of a gigantic star on the verge of exploding, following through with observations of the blast and its aftermath. Their findings have lent support to the reigning theory that stars ranging from tens to hundreds of times the mass of our sun all end up as black holes.

A star's end is predetermined from birth by its size and by the 'power plant' that keeps it shining during its lifetime. Stars, among them our sun, are fueled by hydrogen nuclei fusing together into helium in the intense heat and pressure of their inner cores. A helium nucleus is a bit lighter than the sum of the masses of the four hydrogen nuclei that went into making it and, from Einstein's theory of relativity (E=MC2), we know that the missing mass is released as energy.

When stars like our sun finish off their hydrogen fuel, they burn out relatively quietly in a puff of expansion. But a star that's eight or more times larger than the sun makes a much more dramatic exit. Nuclear fusion continues after the hydrogen is exhausted, producing heavier elements in the star's different layers. When this process progresses to the point that the core of the star has turned to iron, another phenomenon takes over: In the enormous heat and pressure in the star's center, the iron nuclei break apart into their component protons and neutrons. At some point, this causes the core and the layer above it to collapse inward, firing the rest of the star's material rapidly out into space in a supernova flash.

A supernova releases more energy in a few days than our sun will release over its entire lifetime, and the explosion is so bright that one occurring hundreds of light years away can be seen from Earth even in the daytime. While a supernova's outer layers are lighting up the universe with dazzling fireworks, the star's core collapses further and further inward. The gravity created in this collapse becomes so strong that the protons and electrons are squeezed together to form neutrons, and the star's core is reduced from a sphere 10,000 kilometers around to one with a circumference of a mere 10 kilometers. Just a crate-full of this star's material weighs as much as our entire Earth. But when the exploding star is 20 times the mass of our sun or more, say the scientists, its gravitational pull becomes so powerful that even light waves are held in place. Such a star - a black hole - is invisible for all intents and purposes.

Until now, none of the supernovae stars that scientists had managed to measure had exceeded a mass of 20 suns. Gal-Yam and Leonard were looking at a specific region in space using the Keck Telescope on Mauna Kea in Hawaii and the Hubble Space Telescope. Identifying the about-to-explode star, they calculated its mass to be equal to 50-100 suns. Continued observation revealed that only a small part of the star's mass was flung off in the explosion. Most of the material, says Gal-Yam, was drawn into the collapsing core as its gravitational pull mounted. Indeed, in subsequent telescope images of that section of the sky, the star seems to have disappeared. In other words, the star has now become a black hole - so dense that light can't escape.

Dr. Avishai Gal-Yam's research is supported by the Nella and Leon Benoziyo Center for Astrophysics; the Peter and Patricia Gruber Award; the Legacy Heritage Fund; and the William Z. and Eda Bess Novick Young Scientist Fund.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials and developing new strategies for protecting the environment.

Weizmann Institute news releases are posted on the World Wide Web at
http://wis-wander.weizmann.ac.il, and are also available at http://www.eurekalert.org.

Batya Greenman | idw
Further information:
http://wis-wander.weizmann.ac.il
http://wis-wander.weizmann.ac.il/site/en/weizman.asp?pi=371&doc_id=5513
http://www.eurekalert.org

More articles from Physics and Astronomy:

nachricht NASA spacecraft investigate clues in radiation belts
28.03.2017 | NASA/Goddard Space Flight Center

nachricht Researchers create artificial materials atom-by-atom
28.03.2017 | Aalto University

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: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

OLED production facility from a single source

29.03.2017 | Trade Fair News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>