Rare speedy tsunami seen on Sun's surface



Rare speedy tsunami seen on Sun`s surface Zee Media Bureau

New Delhi: In what can be called as an amazing phenomenon, a speedy Tsunami has been observed on the Sun’s surface. We have seen tsunami on earth but now two earth orbiting satellites have seen "tsunami" spreading on the surface of the Sun after a release of matter into space called a coronal mass ejection (CME).

These tsunami of heightened magnetic field and hot, ionised gas race across the Sun at about 400km per second.

Analysis of the chance sighting, to be published in Solar Physics, allowed the measurement of the magnetic field in "quiet" areas, away from the CME.The understanding of this field may help predict how CMEs will affect the Earth.

Collecting the data from Hinode, one of the two satellites, researchers may have cracked a 70-year-old mystery as to why the Sun's surrounding corona is so much hotter than its surface. Hinode is a Japanese satellite which has been studying the Sun since 2006, joined in Earth orbit by the Solar Dynamics Observatory in 2010.

Both satellites look at ultraviolet light from the Sun - colours we cannot see but that give hints as to both the chemical makeup and the extreme physical conditions at and near the Sun's roiling, turbulent surface.

David Long of University College London and colleagues finally spotted what are known as EIT waves after a CME. Like a tsunami emanating from the point of a seismic event, EIT waves are shock waves that carry magnetic fields and hot, ionised "plasma".

"These EIT waves are quite tricky - they're very random and they're relatively rare," Dr Long told BBC News. "We need to be in the right place at the right time; this has been a long time coming."

The SDO satellite was able to capture the ultraviolet light emitted as the wave spread out. From that, the team was able to determine the wave's speed - some 400km per second - and its rough temperature, over a million degrees.

Video at link: http://www.youtube.com/watch?v=Zy6hM06LF3U