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 Breaking the optical bandwidth record of stable pulsed lasers
24.01.2017 | Institut national de la recherche scientifique - INRS

nachricht European XFEL prepares for user operation: Researchers can hand in first proposals for experiments
24.01.2017 | European XFEL GmbH

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: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>