YOU ARE HERE: Home > News & Press > Discovery of exotic supernova sees Dark Energy Survey start off with a bang!

I want information on:

Information for:

NEWS & PRESS

Discovery of exotic supernova sees Dark Energy Survey start off with a bang!

Last Updated on Wednesday, 25 June 2014 08:32
Published on Wednesday, 25 June 2014 01:01

The first images taken by the Dark Energy Survey (DES) after the survey began in August 2013 have revealed a rare, ‘superluminous’ supernova that erupted in a galaxy 7.8 billion light years away. The stellar explosion, called DES13S2cmm, easily outshines most galaxies in the Universe and could still be seen in the data six months later, at the end of the first of what will be five years of observing by DES. The event was discovered by Andreas Papadopoulos, a postgraduate student from the University of Portsmouth, who will present the discovery at the National Astronomy Meeting 2014 in Portsmouth on Wednesday, 25 June.

des1The Milky Way rises over the Cerro Tololo Inter-American Observatory in northern Chile. The Dark Energy Survey operates from the largest telescope at the observatory, the 4-metre Victor M. Blanco Telescope (left). Credit: Andreas Papadopoulos. Click to enlargeSupernovae are very bright, shining anywhere from one hundred million to a few billion times brighter than the Sun for weeks on end. Thousands of these brilliant stellar deaths have been discovered over the last two decades, and the word ‘supernova’ itself was coined 80 years ago. But superluminous supernovae are a recent discovery, only being recognized as a distinct class of objects in the past 5 years. These cosmic explosions are 10-50 times brighter at their peak than the brightest normal type of supernovae and, unlike other supernovae, their explosive origins remain a mystery.

"Fewer than forty such supernovae have ever been found and I never expected to find one in the first DES images!" said Papadopoulos. "As they are rare, each new discovery brings the potential for greater understanding  or more surprises."

It turns out that even within this select group, DES13S2cmm is unusual. The rate that it is fading away over time is much slower than for most other superluminous supernovae that have been observed to date. This change in brightness over time, or 'light curve', gives information on the mechanisms that caused the explosion and the composition of the material ejected.

Dr Mark Sullivan of Southampton University led the program to obtain spectroscopy of DES13S2cmm using the Very Large Telescope at Cerro Paranal, Chile. "Its unusual, slow decline was not apparent at first," said Sullivan, "but as more data came in and the supernova stopped getting fainter, we would look at the light curve and ask ourselves, 'what is this?'"

Understanding the origins of DES13S2cmm is proving difficult. Radioactive decay is known to power normal supernovae, but not from such extreme amounts of material.

"We have tried to explain the supernova as a result of the decay of the radioactive isotope Nickel-56," explained Dr Chris D'Andrea of the University of Portsmouth, co-author on the research, "but to match the peak brightness, the explosion would need to produce more than three times the mass of our Sun of the element. And even then the behaviour of the light curve doesn’t match up."

des2Before (left) and after (center) images of the region where DES13S2cmm was discovered. On the right is a subtraction of these two images, showing a bright new object at the center -- a supernova. Credit: Dark Energy Survey. Click to enlarge

The team are now investigating alternative explanations, including that DES13S2cmm is a normal supernova that has created at its core a magnetar -- an exotic neutron star spinning hundreds of times per second, producing a magnetic field a trillion times stronger than that on Earth. Energy from the magnetar is then injected into the supernova, making the explosion exceptionally bright. "Neither model is a particularly compelling match to the data," noted D’Andrea.

With DES starting its second season in August, the hunt is on for more superluminous supernovae.

"With so few known, it’s hard to really understand their properties in detail," said Prof. Bob Nichol of the University of Portsmouth. "DES should find enough of these objects to allow us to understand superluminous supernovae as a population. But if some of these discoveries prove as difficult to interpret as DES13S2cmm, we’re prepared for the unusual!"

 

Media contacts

NAM 2014 press office landlines: +44 (0) 02392 845176, +44 (0)2392 845177, +44 (0)2392 845178

Dr Robert Massey
Mob: +44 (0)794 124 8035
This email address is being protected from spambots. You need JavaScript enabled to view it.

Anita Heward
Mob: +44 (0)7756 034 243
This email address is being protected from spambots. You need JavaScript enabled to view it.

Dr Keith Smith
This email address is being protected from spambots. You need JavaScript enabled to view it.

An ISDN line is available for radio interviews. To request its use, please contact Sophie Hall via This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Science contact

Andreas Papadopoulos
Institute of Cosmology and Gravitation
University of Portsmouth
This email address is being protected from spambots. You need JavaScript enabled to view it.

Dr Chris D’Andrea
Institute of Cosmology and Gravitation
University of Portsmouth
This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Images and captions

https://www.ras.org.uk/images/stories/NAM/2014/des1.jpg
The Milky Way rises over the Cerro Tololo Inter-American Observatory in northern Chile. The Dark Energy Survey operates from the largest telescope at the observatory, the 4-metre Victor M. Blanco Telescope (left). Credit: Andreas Papadopoulos.

https://www.ras.org.uk/images/stories/NAM/2014/des2.jpg
Before (left) and after (center) images of the region where DES13S2cmm was discovered. On the right is a subtraction of these two images, showing a bright new object at the center -- a supernova. Credit: Dark Energy Survey

 

Further information

The Dark Energy Survey is a 5 year, 525 night optical imaging survey using DECam, a purpose-built wide-field imaging camera installed and commissioned on the 4-meter Blanco Telescope at Cerro Tololo Inter-American Observatory, Chile. Over the course of the survey DES will find and measure over 5000 supernovae and map 300 million galaxies. Six universities in the United Kingdom (Cambridge, Edinburgh, Nottingham, Portsmouth, Sussex, UCL) are members of the International DES Collaboration. The DES optical corrector was constructed at UCL with funding provided by STFC and the UK DES collaboration.

Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência e Tecnologia, the Deutsche Forschungsgemeinschaft and the Collaborating Institutions in the Dark Energy Survey.

The Collaborating Institutions are Argonne National Laboratories, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the Eidgenoessische Technische Hochschule (ETH) Zurich, Fermi National Accelerator Laboratory, the University of Edinburgh, the University of Illinois at Urbana-Champaign, the Institut de Ciencies de l'Espai (IEEC/CSIC), the Institut de Fisica d'Altes Energies, the Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universität and the associated Excellence Cluster Universe, the University of Michigan, the National Optical Astronomy Observatory, the University of Nottingham, the Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, and Texas A&M University.

 

Notes for editors

The RAS National Astronomy Meeting (NAM 2014) will bring together more than 600 astronomers, space scientists and solar physicists for a conference running from 23 to 26 June in Portsmouth. NAM 2014, the largest regular professional astronomy event in the UK, will be held in conjunction with the UK Solar Physics (UKSP), Magnetosphere Ionosphere Solar-Terrestrial physics (MIST) and UK Cosmology (UKCosmo) meetings. The conference is principally sponsored by the Royal Astronomical Society (RAS), the Science and Technology Facilities Council (STFC) and the University of Portsmouth. Meeting arrangements and a full and up to date schedule of the scientific programme can be found on the official website and via Twitter.

The University of Portsmouth is a top-ranking university in a student-friendly waterfront city. It's in the top 50 universities in the UK, in The Guardian University Guide League Table 2014 and is ranked in the top 400 universities in the world, in the most recent Times Higher Education World University Rankings 2013. Research at the University of Portsmouth is varied and wide ranging, from pure science – such as the evolution of galaxies and the study of stem cells – to the most technologically applied subjects – such as computer games design. Our researchers collaborate with colleagues worldwide, and with the public, to develop new insights and make a difference to people's lives. Follow the University of Portsmouth on Twitter.

The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3800 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others. Follow the RAS on Twitter.

The Science and Technology Facilities Council (STFC) is keeping the UK at the forefront of international science and tackling some of the most significant challenges facing society such as meeting our future energy needs, monitoring and understanding climate change, and global security. The Council has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar. It enables UK researchers to access leading international science facilities for example in the area of astronomy, the European Southern Observatory. Follow STFC on Twitter.