Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

‘Wild Cousin’ Emerges from Family Tree of Supernova

26.09.2008
Astronomers may have discovered the relative of a freakishly behaving exploding star once thought to be the only one of its kind.

For more than two decades, astronomers have intensively studied supernova 1987A, an exploding star that had behaved like no other. Instead of growing dimmer with time, 1987A has grown brighter at X-ray and radio wavelengths.

A team of astronomers that includes the University of Chicago’s Vikram Dwarkadas is asking if supernova 1996cr, discovered by Columbia University’s Franz Bauer, is actually the “wild cousin” of supernova 1987A.

“This may be the second case, after ‘87a, where we see emission that’s increasing dramatically,” said Dwarkadas, Senior Research Associate in Astronomy & Astrophysics at Chicago. “Normally, you would expect the emission to decrease over time.”

In a new paper published in the Astrophysical Journal, Bauer, Dwarkadas and five co-authors call 1996cr a potential “wild cousin” of the earlier supernova. “These two look alike in many ways, except this newer supernova is intrinsically 1,000 times brighter,” Bauer said.

Supernova 1996cr is located 12 million light years from Earth in the spiral galaxy Circinus, making it one of the nearest-known exploding stars of the last quarter-century.

When 1996cr exploded in the mid-1990s, no one noticed. Bauer first detected the object in 2001 using NASA’s Chandra X-ray Observatory. Although intrigued by its exceptional qualities, Bauer, then at Pennsylvania State University, and his associates were unable to verify it as a supernova.

But recently acquired data from the European Southern Observatory’s Very Large Telescope in Chile prompted further investigation. After searching archival images from Australia’s Anglo-Australian Telescope, Bauer determined that the explosion occurred between Feb. 28, 1995, and March 15, 1996.

All told, Bauer’s team examined data from 18 different telescopes, both orbiting and ground-based, nearly all of it coming from the observatories’ Internet archives.

Most supernovas grow dimmer with the passage of time as they release their energy. But the X-ray and radio emissions from 1987A grew brighter because its shock wave had crashed into a dense cloud of gas and dust. Supernova shock waves initially move at speeds of 10,000 miles or more each second.

According to the calculations of Dwarkadas and other theoreticians, these interstellar gas clouds form a bubble around stars at least eight times more massive than the sun, possibly the product of smaller upheaval or a lifetime of mass-loss from solar wind emissions that took place before the supernova.

These wind-blown bubbles, as astronomers call them, are like a balloon: empty in the middle with a shell around the outside. The explosion moves rapidly through the cavity for several years because there’s almost nothing to stop it. “Then it hits this dense shell. It slows down and begins to give off a lot of emission,” Dwarkadas said.

Supernovas close enough to be studied in such detail come by only once a decade, Bauer said. “It’s a bit of a coup to find SN1996cr in the manner we did, and we could never have nailed it without the serendipitous data taken by all of these telescopes. We’ve truly entered a new era of ‘Internet astronomy,’” he said.

Co-authors of the paper included Niel Brandt, Penn State; Stefan Immler, NASA Goddard Space Flight Center; Norbert Bartel, York University, Canada; and Michael Bietenholz, York University and Hartebeesthoek Radio Observatory, South Africa. The National Science Foundation, the National Aeronautic and Space Administration, and the European Science Foundation provided funding.

Steve Koppes | Newswise Science News
Further information:
http://www.uchicago.edu

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

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: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

The Maturation Pattern of the Hippocampus Drives Human Memory Deve

23.07.2018 | Science Education

FAU researchers identify Parkinson's disease as a possible autoimmune disease

23.07.2018 | Health and Medicine

O2 stable hydrogenases for applications

23.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>