Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NuSTAR helps untangle how stars explode

20.02.2014
For the first time, an international team of astrophysicists, including Lawrence Livermore National Laboratory scientists, have unraveled how stars blow up in supernova explosions.

Using NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) -- a high-energy X-ray observatory -- the international collaboration created the first-ever map of radioactive material in a supernova remnant, named Cassiopeia A, or Cas A for short. The findings reveal how shock waves likely rip apart massive dying stars, and ultimately end their lives.


The NuSTAR high-energy X-ray observatory captured this image of Cassiopeia A, a remnant that blew up as a supernova more than 11,000 years ago, leaving a dense stellar corpse and its ejected remains. Because the supernova was so far from Earth, the light only reached Earth about 350 years ago, when it may have appeared to be a new, bright star in the sky.

A supernova is the cataclysmic death of a star, which is extremely luminous and causes a burst of radiation that often briefly outshines an entire galaxy before fading from view. The explosion expels much or all of a star's material at a velocity of 10 percent of the speed of light, driving a shock wave into the surrounding interstellar medium. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant.

"Stars are spherical balls of gas, and so you might think that when they end their lives and explode, that explosion would look like a uniform ball expanding out with great power," said Fiona Harrison, the principal investigator of NuSTAR at the California Institute of Technology and one of the lead authors of a new paper. "Our new results show how the explosion's heart, or engine, is distorted, possibly because the inner regions literally slosh around before detonating."

The research appears in the Feb. 20 issue of the journal Nature.

The Cas A remnant was created when a massive star blew up as a supernova more than 11,000 years ago, leaving a dense stellar corpse and its ejected remains. Because the supernova was so far from Earth, the light only reached Earth about 350 years ago, when it may have appeared to be a new, bright star in the sky.

Supernovae seed the universe with many elements, including gold, calcium and iron. While small stars like our sun die less violent deaths, stars with about eight times the mass of our sun or greater blow up in supernova explosions. The high temperatures and particles created in the blast cause fusion of lighter elements into heavier ones.

NuSTAR is the first telescope capable of producing maps of radioactive material in supernova remnants; in this case, titanium-44, an atom with an unstable nucleus produced at the heart of the exploding star.

"Cas A was a mystery for so long but now with the map of radioactive material, we're getting a more complete picture of the core of the explosion," said Bill Craig, an LLNL scientist now at UC Berkeley and co-author of the paper.

The NuSTAR map of Cas A, which shows the titanium concentrated in clumps at the remnant's center, points to a possible solution to the mystery of how the star met its demise. When researchers simulate supernova blasts with computers, the main shock wave stalls out and the star fails to shatter.

"For NuSTAR, Cas A is special," said Mike Pivovaroff, a LLNL physicist and a co-author on the new paper. "One of NuSTAR's science goals is to map recently synthesized material in young supernova remnants, and Cas A is one of the youngest supernova remnants we know of."

The latest findings strongly suggest the exploding star literally sloshed around, reenergizing the stalled shock wave and allowing the star to blast off its outer layers.

NuSTAR, a NASA Explorer-class mission launched in June of 2012, is uniquely designed to detect the highest-energy X-ray light in great detail. For Livermore, the predecessor to NuSTAR was a balloon-borne instrument known as HEFT (the High Energy Focusing Telescope) that was funded, in part, by a Laboratory Directed Research and Development investment beginning in 2001. NuSTAR takes HEFT's X-ray focusing abilities and sends them beyond Earth's atmosphere on a satellite. The optics principles and the fabrication approach for NuSTAR are based on those developed under the HEFT project. Craig serves as the NuSTAR instrument manager while Pivovaroff and LLNL scientist Julia Vogel are part of the optics team.

Founded in 1952, Lawrence Livermore National Laboratory provides solutions to our nation's most important national security challenges through innovative science, engineering and technology. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.

Anne M Stark | EurekAlert!
Further information:
http://www.llnl.gov

More articles from Physics and Astronomy:

nachricht Enhancing the quantum sensing capabilities of diamond
23.11.2017 | The Hebrew University of Jerusalem

nachricht Quantum optics allows us to abandon expensive lasers in spectroscopy
22.11.2017 | Lomonosov Moscow State 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: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>