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 Initial repulsion does not rule out subsequent attraction
13.09.2019 | Universität Regensburg

nachricht NASA's Hubble finds water vapor on habitable-zone exoplanet for 1st time
12.09.2019 | NASA/Goddard Space Flight Center

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: The working of a molecular string phone

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Potsdam (both in Germany) and the University of Toronto (Canada) have pieced together a detailed time-lapse movie revealing all the major steps during the catalytic cycle of an enzyme. Surprisingly, the communication between the protein units is accomplished via a water-network akin to a string telephone. This communication is aligned with a ‘breathing’ motion, that is the expansion and contraction of the protein.

This time-lapse sequence of structures reveals dynamic motions as a fundamental element in the molecular foundations of biology.

Im Focus: Milestones on the Way to the Nuclear Clock

Two research teams have succeeded simultaneously in measuring the long-sought Thorium nuclear transition, which enables extremely precise nuclear clocks. TU Wien (Vienna) is part of both teams.

If you want to build the most accurate clock in the world, you need something that "ticks" very fast and extremely precise. In an atomic clock, electrons are...

Im Focus: Graphene sets the stage for the next generation of THz astronomy detectors

Researchers from Chalmers University of Technology have demonstrated a detector made from graphene that could revolutionize the sensors used in next-generation space telescopes. The findings were recently published in the scientific journal Nature Astronomy.

Beyond superconductors, there are few materials that can fulfill the requirements needed for making ultra-sensitive and fast terahertz (THz) detectors for...

Im Focus: Physicists from Stuttgart prove the existence of a supersolid state of matte

A supersolid is a state of matter that can be described in simplified terms as being solid and liquid at the same time. In recent years, extensive efforts have been devoted to the detection of this exotic quantum matter. A research team led by Tilman Pfau and Tim Langen at the 5th Institute of Physics of the University of Stuttgart has succeeded in proving experimentally that the long-sought supersolid state of matter exists. The researchers report their results in Nature magazine.

In our everyday lives, we are familiar with matter existing in three different states: solid, liquid, or gas. However, if matter is cooled down to extremely...

Im Focus: World record for tandem perovskite-CIGS solar cell

A team headed by Prof. Steve Albrecht from the HZB will present a new world-record tandem solar cell at EU PVSEC, the world's largest international photovoltaic and solar energy conference and exhibition, in Marseille, France on September 11, 2019. This tandem solar cell combines the semiconducting materials perovskite and CIGS and achieves a certified efficiency of 23.26 per cent. One reason for this success lies in the cell’s intermediate layer of organic molecules: they self-organise to cover even rough semiconductor surfaces. Two patents have been filed for these layers.

Perovskite-based solar cells have experienced an incredibly rapid increase in efficiency over the last ten years. The combination of perovskites with classical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

AI for Laser Technology Conference: optimizing the use of lasers with artificial intelligence

29.08.2019 | Event News

 
Latest News

Low sea-ice cover in the Arctic

13.09.2019 | Earth Sciences

Researchers produce synthetic Hall Effect to achieve one-way radio transmission

13.09.2019 | Power and Electrical Engineering

Penn engineers' new topological insulator reroutes photonic 'traffic' on the fly

13.09.2019 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>