White Dwarf confirmed as main contender for explosions
16 December 2011
White Dwarf confirmed as main contender for explosions used to study the expansion of the Universe.
Astronomers have spotted the nearest type Ia supernova in a generation with the help of LJMU's Liverpool Telescope (LT). Type I a supernovae (exploding stars) are used to understand how fast the Universe expands. This event, dubbed SN 2011fe, allowed astronomers to confirm that exploding White Dwarf stars are the cause of these cosmic explosions. Initial results since this discovery in August, have now been published in Nature*.
This discovery of a close supernova of this type means that researchers now have access to enhanced quality data to understand the origin, expansion, and fate of the Universe and have already uncovered important results.
Scientists from the Palomar Transient Factory (PTF) collaboration made the discovery using a robotic telescope in California in the United States. They used the Liverpool Telescope, owned and operated by the Astrophysics Research Institute (ARI) to obtain the spectrum essential in identifying that it was a supernovae type Ia supernova.
Type Ia SNe are essential to astronomers in realising the expansion of the Universe is accelerating, which was a discovery that gained the Nobel prize in Physics this year. The closest supernova of this type was last spotted in 1972. Already astronomers have been able to use the spectrum provided by the Liverpool Telescope to show that nuclear reactions occurring during supernovae explosions are not burning all their Oxygen and Carbon. This means that astronomers researching Supernovae of type 1a know now that not all of them burn their nuclear fuel. This will provide a better understanding of these explosions which in turn, allows a better understanding of the expansion of the Universe.
Another important result of the paper is the size of the progenitor star (stars that have been through several successive stages of evolution). White dwarf stars explosions are the preferred models for research, but are so faint they are often not detected in pre-explosion images. The data collected in the first few days of this discovery by the Liverpool Telescope proved that this progenitor was a Carbon/Oxygen white dwarf and is officially the main "contender" for SNe Ia research.
Oxford team leader, Dr Mark Sullivan, triggered the LT observations as part of a collaboration between LJMU and Oxford. Dr Sullivan said that the LT's rapid-response capability enabled 'probably the earliest SN Ia spectrum ever taken'.
LJMU Astronomer David Bersier said:
"White dwarfs have been suspected of being the progenitors of SNe Ia but the paper puts solid constraints on that. Now we can be sure that white dwarfs are the progenitors of SNe Ia. It took about three hours to go from the discovery of the supernova candidate by a computer in California to establishing the true nature of this explosion. This is because a telescope like the Liverpool Telescope is the ideal machine to respond to events like supernovae that happen without warning."
Dr Mark Sullivan added:
"The most exciting thing is that this is what's known as a type 1a supernova - the kind we use to measure the expansion of the Universe. Seeing one explode so close by allows us to study these events in unprecedented detail."
The Palomar Transient Factory is a wide-field survey operated at the Palomar Observatory by the California Institute of Technology on behalf of a worldwide consortium of partner institutions. Collaborating institutions are Caltech, Columbia University, Las Cumbres Observatory Global Telescope, Lawrence Berkeley National Laboratory, UC Berkeley, University of Oxford, and the Weizmann Institute of Science (Israel).
The story was featured in The Guardian http://www.guardian.co.uk/science/2011/dec/14/supernova-explosion-glimpse-life-created?newsfeed=true
Hubble Racks Up 10,000 Science Papers
Additionally the ARI recently celebrated helping NASA's Hubble Space Telescope reach another milestone in its 21 years of exploration when the 10,000th refereed science paper was published. The paper's lead authors were Zach Cano, a recently graduated LJMU PhD student and his supervisor Dr David Bersier, LJMU Astronomer of the ARI. They reported on the identification of the faintest supernova ever associated with a long-duration gamma-ray burst - an intense gusher of high-energy radiation following the death of a star.
This makes Hubble one of the most prolific astronomical endeavors in history. The 10,000th paper's lead author was Zach Cano of the ARI. He reported on the identification of the faintest supernova ever associated with a long-duration gamma-ray burst - an intense gusher of high-energy radiation following the death of a star.
See the full release at:
Further information about the Liverpool Telescope is available at: http://www.astro.ljmu.ac.uk/about/ltproject.shtml