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The Sun's magnetic fountains (Forwarded)
ROYAL ASTRONOMICAL SOCIETY PRESS INFORMATION NOTE
Issued by RAS Press Officers: Dr Robert Massey Tel: +44 (0)20 7734 3307 / 4582 Anita Heward Tel: +44 (0)1483 420904 NATIONAL ASTRONOMY MEETING PRESS ROOM (31 MARCH - 4 APRIL ONLY): Tel: +44 (0)2890 975262 / 975263 / 975264 NAM 2008 http://nam2008.qub.ac.uk Royal Astronomical Society http://www.ras.org.uk CONTACTS: Dr Michelle Murray Mullard Space Science Laboratory University College London Tel: +44 (0)1483 204211 Deb Baker Mullard Space Science Laboratory University College London Tel: +44 (0)1483 204179 Jenny Gimpel Media Relations Manager UCL Development & Corporate Communications Office University College London Gower Street London WC1E 6BT Tel: +44 (0)20 7679 9726 Web: www.ucl.ac.uk/media EMBARGOED UNTIL 0001 BST, 2 April 2008 Ref.: PN 08/26 (NAM 17) The Sun's magnetic fountains Astronomers have known for decades that the Sun has a very dynamic atmosphere. Huge fountains of hot gas erupt in the atmosphere, or corona, every few minutes, travelling at tens of thousands of km per hour and reaching great heights. Now a team of scientists have used the Hinode spacecraft to find the origin and driver of these fountains -- immense magnetic structures that thread through the solar atmosphere. On Wednesday 2 April at the Royal Astronomical Society National Astronomy Meeting in Belfast (NAM 2008), team leader Dr Michelle Murray from the Mullard Space Science Laboratory (MSSL, University College London) will present the latest results from Hinode together with computer simulations that model conditions on the Sun. Since its launch in October 2006, scientists have been using Hinode to examine the solar atmosphere in extraordinary detail. One of the instruments on the space observatory, the Extreme Ultraviolet Imaging Spectrometer (EIS) built by a consortium led by MSSL, generates images of the Sun and gives information on how fast its gases are moving. Increases in pressure at the base of the Sun's magnetic field cause enormous jets of hot gas to shoot upwards into the solar atmosphere. Once the pressure ceases, the hot gases stop soaring into the atmosphere and fall back towards the solar surface. The changes in pressure are caused by rearrangements of the Sun's magnetic field, a continual process that results in looping cycles of increasing and decreasing pressure and, consequentially, intermittent solar fountains. "EIS has observed the Sun's fountains in unprecedented detail and it has enabled us to narrow down the fountains' origins for the first time," comments team member and MSSL postgraduate student Deb Baker. "We have also been able to find what drives the fountains by using computer experiments to replicate solar conditions." "The computer experiments demonstrate that when a new section of magnetic field pushes through the solar surface it generates a continual cycle of fountains," explains Dr Murray, "but new magnetic fields are constantly emerging across the whole of the solar surface and so our results can explain a whole multitude of fountains that have been observed with Hinode." IMAGES AND MOVIES Images and movies of the fountains: http://www.mssl.ucl.ac.uk/~mjm/NAM08/ Image and movie captions Figure 1: During a total solar eclipse the Moon passes in front of the Sun, blocking out the most intense solar light and allowing us to view the Sun's atmosphere, or corona, from Earth. The Sun's light can be seen streaming through the immense magnetic structures that thread through the corona and stretch out into space. Image credit: Luc Viatour GFDL/CC Movie 1: At the northern pole of the Sun, an incredibly fast fountain of hot gases shoots above the edge of the solar disk into the atmosphere before falling back down to the surface. In the foreground, gases bubble away at temperatures approaching millions of degrees Celsius. This movie was assembled from images captured with the EIS instrument, aboard the Hinode spacecraft, on 1 April 2007. Movie: Jian Sun / MSSL / UCL / JAXA / NAOJ / NASA / ESA / NSC FURTHER INFORMATION * Mullard Space Science Laboratory http://www.mssl.ucl.ac.uk * ESA http://www.esa.int * JAXA http://www.jaxa.jp * NASA http://www.nasa.gov * NSC http://www.spacecentre.no NOTES FOR EDITORS The Hinode (Japanese for sunrise) mission was launched in October 2006. It is used to study magnetic fields on the Sun and their role in powering the solar atmosphere and driving solar eruptions. Hinode was developed and launched by the Japanese Space Agency ISAS/JAXA, with the National Astronomical Observatory of Japan (NAOJ) as the domestic partner and NASA and the UK Science and Technology Facilities Council (STFC) as international partners. It is operated by these agencies in co-operation with the European Space Agency (ESA) and the Norwegian Space Centre (NSC). The Extreme Ultraviolet Imaging Spectrometer (EIS) was built by a consortium led by MSSL. The RAS National Astronomy Meeting (NAM 2008) is hosted by Queen's University Belfast. It is principally sponsored by the RAS and the Science and Technology Facilities Council (STFC). NAM 2008 is being held together with the UK Solar Physics (UKSP) and Magnetosphere, Ionosphere and Solar-Terrestrial (MIST) spring meetings. |
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