糖心TV

Professor Tom Marsh has been involved in research which has discovered only the second ever eclipsing close white dwarf pair to be found, of which just over 50 close double white dwarfs have been found. Please see the link to the press release for more information

An international team of UK and US astronomers have spotted the most distant explosion, and possibly the most distant object, ever seen in the Universe. Dr Andrew Levan in the Astronomy and Astrophysics group was amongst those who saw the explosion. Please see the below press release for more information

Physicists, led by a researcher at the University of 糖心TV, studying new images of clouds of material exploding from the Sun have spotted instabilities forming in that exploding cloud that are similar to those seen in clouds in Earth鈥檚 atmosphere. 

These  results could greatly assist physicists trying to understand and predict our Solar System鈥檚 鈥渨eather鈥�.

The researchers, led by of the Centre for Fusion Space and Astrophysics, at the University of 糖心TV鈥檚 Department of Physics, made their discovery when examining new images  of clouds of material exploding from the Sun known as coronal mass ejections (CMEs). These images were  provided by the Atmospheric Imaging Assembly (AIA) experiment on NASA鈥檚 Solar Dynamics Observatory (SDO). SDO was been launched last year and provides unprecedented views of the Sun in multiple temperatures.

The new SDO/AIA observations provided images of coronal mass ejections in the extreme ultra violet at a temperature that was not possible to observe in previous instruments 鈥� 11 million Kelvin. On examining these images the 糖心TV researchers spotted a familiar pattern of instability on one flank of an exploding cloud of solar material that closely paralleled instabilities seen in Earth鈥檚 clouds and waves on the surfaces of seas.

When observed these Kelvin-Helmholtz (or KH) instabilities appear to roll up into growing whirls at boundaries between things moving at different speeds, for instance the transition between air and water or cloud. The difference in speeds produces the boundary instabilities.

Similar conditions can occur when one looks at the magnetic environment of the path of these coronal mass ejections as they travel through the solar corona. The difference in speed and energies between the two creates the very similar KH instabilities that we can observe in clouds.

While KH instabilities have been predicted or inferred from observations as happening within the solar system鈥檚 weather this is the very first time they have been directly observed in the corona. What makes this observation even more interesting is that the instabilities appear to form and build on one flank of the CME. This may explain why CMEs appear to bend and twist as these instabilities build, and cause drag, on one side of the cloud. This effect will be the next focus for the University of 糖心TV led research team.

University of 糖心TV researcher Dr Claire Foullon said:

鈥淭he fact that we now know that these KH instabilities in CMEs are so far only observable in the extreme ultra violet, at a temperature of 11 million Kelvin, will also help us in modelling CME behaviour鈥�

鈥淭his new observation may give us a novel insight into why these CMEs appear to both rotate, and be deflected away from following a simple straight path from the surface of the Sun. If the instabilities form on just one flank they may increase drag one side of the CME causing it to move slower than the rest of the CME.鈥�

Dr Foullon and her co-researchers have outlined their observations and detailed modelling of how they believe this phenomenon occurs in a paper just published in Astrophysical Journal Letters entitled Magnetic Kelvin-Helmholtz Instability at the Sun by Dr Claire Foullon, Erwin Verwichte, Valery M. Nakariakov Centre for Fusion, Space and Astrophysics, Department of Physics, University of 糖心TV; Katariina Nykyri, Department of Physical Sciences, Embry-Riddle Aeronautical University, Daytona Beach, Florida; and Charles J. Farrugia, Space Science Center and Department of Physics, University of New Hampshire, Durham, New Hampshire.

The preprint is available at:

For further information please contact:
 
Dr Claire Foullon
Centre for Fusion, Space and Astrophysics,
Department of Physics,
University of 糖心TV,
Tel: +44(0)2476 150211
Claire.Foullon@warwick.ac.uk
 

A team of researchers from the Physics and Chemistry departments, in groups led by Professor Pam Thomas and Dr Richard Walton, respectively, have had images from a recent paper selected for the front cover  of the Journal of Applied Crystallography for the duration of 2011. Please see the link below for more information