Secrets of the Solar Wind

Scientists working on the Hinode space mission believe they have may have witnessed the origin of the Solar Wind for the first time. Solar Wind is a flow of plasma from the Sun throughout space – it bombards the Earth and can be hazardous for electronics and people if they are not adequately protected against it. Their results are published in Science (7th December 2007).

Professor Louise Harra of UCL’s Mullard Space Science Laboratory said "The solar wind bombards the Earth at speeds of hundreds of kilometres per second. However the actual source of the wind and the mechanisms by which it is created have been unclear. Using Hinode, my colleagues and I have been able to study never before seen details of the Sun and identify a possible source of the Solar Wind, where material could clearly be seen streaming from the Sun."

Hinode discovered rapid moving extended structures at the edges of active regions in the Sun and clearly identified that these have material flowing out from them. Estimates based on the temperature and density of the material suggest this could form as much as a quarter of the total solar wind.

Hinode (Sunrise in Japanese) was launched to study magnetic fields on the Sun and their role in powering the solar atmosphere and driving solar eruptions. Hinode is a Japanese mission developed and launched by ISAS/JAXA, with NAOJ as domestic partner and NASA and STFC (UK) as international partners. It is operated by these agencies in co-operation with ESA and NSC (Norway).

• Read the Japanese announcement (link opens in a new window) of this result and the full author listing
• Read the NASA announcement (link opens in a new window)

Notes for Editors

Images

Low resolution (Science data) images are available showing:-

• Image 1 - The corona of active region adjacent to a coronal hole, seen by XRT/Hinode. A circle in the bottom indicates the size of the Earth.
  Copyright NAOJ/JAXA/NASA/STFC/ESA
• Image 2 - Magnetic field extrapolation that shows the magnetic field lines extending out into interplanetary space. Credit Taro Sakao, ISAS/JAXA

Press Contact

• Julia Maddock
  Science and Technology Facilities Council
  Press Office
  Tel: +44 (0)1793 442 094
  Mob: +44 (0)7901 514 975

Science Contacts

• Prof Louise Harra
  Mullard Space Science Laboratory
  University College London
  Tel: +44 (0)20 7679 3157
  Mob: +44 (0)774 7439 7283
  
  
• Taro Sakao
  Institute of Space and Astronautical Science
  Japan Aerospace Exploration Agency
  3-1-1 Yoshinodai
  Sagamihara
  Kanagawa 229-8510
  Tel: +81 427 598 210
  Fax: +81 427 598 526
  
  
• Dr Bernhard Fleck
  ESA SOHO and Hinode Project Scientist
  
  
• Dr Pål Brekke
  Senior Advisor
  Norwegian Space Centre

About Hinode

The sun-observing Hinode satellite (formerly Solar-B) of the Japan Aerospace Exploration Agency (JAXA) was launched from the Uchinoura Space Center, Kagoshima Prefecture, Kyushu, Japan, on September 22, 2006 at 21:36 GMT, aboard the seventh in JAXA’s series of M-V rockets. Hinode is in a sun-synchronous orbit, which allows it to observe the sun for uninterrupted periods lasting months at a time. Hinode contains three instruments dedicated to observing the sun: the Solar Optical Telescope (SOT), the X-Ray Telescope (XRT), and the EUV Imaging Spectrometer (EIS).

Hinode is a Japanese mission developed and launched by ISAS/JAXA, with NAOJ as domestic partner and NASA and STFC (UK) as international partners. It is operated by these agencies in co-operation with ESA and NSC (Norway).

In partnership with the Norwegian Space Centre in Oslo, ESA is providing ground station coverage through the Svalbard Satellite Station, situated on the Norwegian Svalbard islands. This is the only ground station in the world that can receive the satellite data for each of Hinode's 15 daily orbits, enabling a dramatic increase in scientific output.

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