'Pipe organ' plays above the Sun
2007 04 21

By Paul Rincon | news.bbc.co.uk


Coronal loops are generated by the Sun's magnetic field. Listen: Acoustic waves
Immense coils of hot, electrified gas in the Sun's atmosphere behave like a musical instrument, scientists say.


These "coronal loops" carry acoustic waves in much the same way that sound is carried through a pipe organ.

Solar explosions called micro-flares generate sound booms which are then propagated along the coronal loops.

"The effect is much like plucking a guitar string," Professor Robert von Fay-Siebenbuergen told BBC News at the National Astronomy Meeting in Preston.

The corona is an atmosphere of hot, electrically-charged gas - or plasma - that surrounds the Sun. The temperature of the corona should drop the further one moves from the Sun.

But, in fact, the coronal temperature is up to 300 times hotter than the Sun's visible surface, or photosphere. And no one can explain why.

Fiery fountains
The coronal loops arch hundreds of thousands of kilometres above the Sun's surface like huge fiery fountains, and are generated by the Sun's magnetic field.

As solar plasma travels from the photosphere into the loops, it is heated from about 6,000 Kelvin (5,700C) to upwards of one million Kelvin.

Solar explosions called micro-flares can release energy equivalent to millions of hydrogen bombs.

These blasts can send immensely powerful acoustic waves hurtling through the loops at tens of kilometres per second, creating cosmic "organ music".

"These loops can be up to 100 million kilometres long and guide waves and oscillations in a similar way to a pipe organ," said Dr Youra Taroyan, from the Solar Physics and Space Plasma Research Centre (SP2RC) at the University of Sheffield.

The sound booms decay in less than an hour and dissipate in the very hot solar corona.

Professor von Fay-Siebenbuergen, who is director of SP2RC, said that studying how plasma is heated to such high temperatures in coronal loops could speed up the technological development of industrial-scale nuclear fusion on Earth.

'Star on Earth'
Nuclear fusion is the same process which powers the Sun and other stars. Unlike the burning of fossil fuels, fusion reactions produce no carbon dioxide, the greenhouse gas blamed by scientists for warming the planet.

Fusion works on the principle that energy can be released by forcing together atomic nuclei rather than by splitting them, as in the case of the fission reactions that drive existing nuclear power stations.

In the core of the Sun, huge gravitational pressure allows this to happen at temperatures of around 10 million Celsius.

At the much lower pressure that is possible on Earth, temperatures to produce fusion need to be much higher - above 100 million Celsius

In nuclear fusion experiments, powerful magnetic fields can be used to isolate hot plasma from the walls of a containment vessel.

This reduces the conductive heat loss, allowing the electrified gas to be heated to high temperatures.

The most promising magnetic confinement systems are ring-shaped; called a torus.

Professor von Fay-Siebenbuergen said a coronal loop could give clues to improving nuclear fusion because it could be regarded as a half-torus.

The Royal Astronomical Society's National Astronomy Meeting in Preston runs from 16-20 April.

Article from: http://news.bbc.co.uk/2/hi/science/nature/6574059.stm



Related Articles
The Electric Glow Of The Sun
A Case For The Sun to Be Alive
The Explosion that Shattered Solar Theory
Solar flares will disrupt GPS in 2011
Sunspot Cycles & Natural Disasters
Sunspots and Earthquakes
SUV's On Jupiter? - Solar System Warming
The truth about global warming - it's the Sun that's to blame
Forgotten In Time: The Ancient Solfeggio Frequencies
Red Ice Radio - Donald E. Scott - The Electric Sky


Latest News from our Front Page

Illegal Aliens Cleared For U.S. Military Service
2014 10 18
The Pentagon announced a new policy allowing illegal immigrants the opportunity to enlist in the armed forces, Thursday. USA Today reports that the new recruitment policies will focus on people with "high-demand skills" like foreign language acumen and health care training: "For the first time, the program — known as Military Accessions in the National Interest, or MAVNI — will ...
Bronze Age Sundial-Moondial Discovered in Russia
2014 10 16
A strange slab of rock discovered in Russia more than 20 years ago appears to be a combination sundial and moondial from the Bronze Age, a new study finds. The slab is marked with round divots arranged in a circle, and an astronomical analysis suggests that these markings coincide with heavenly events, including sunrises and moonrises. The sundial might be "evidence of ...
Humans may only survive 68 days on Mars
2014 10 15
Space enthusiasts planning a move to Mars may have to wait to relocate: conditions on the Red Planet are such that humans would likely begin dying within 68 days, a new study says. Oxygen levels would start to deplete after about two months and scientists said new technologies are required before humans can permanently settle on Mars, according to the study ...
Tom Sunic’s letter to the US Ambassador to Hungary
2014 10 14
October 11, 2014 Mr. André Goodfriend Chargé d’Affaires Embassy of the United States of America Szabadság tér 12 H-1054 Budapest Dear Mr. Goodfriend, As an American citizen I would hereby like to express my concern over the recent decision by the Hungarian government to ban the National Policy Institute (NPI) conference which had been scheduled to take place in Budapest from October 3 to October 5, 2014. ...
"Vampire grave" found in Bulgaria
2014 10 14
A "vampire grave" containing a skeleton with a stake driven through its chest has been unearthed by a man known as "Bulgaria’s Indiana Jones". Professor Nikolai Ovcharov – a crusading archaeologist who has dedicated his life to unearthing mysteries of ancient civilisations – said that he had made the discovery while excavating the ruins of Perperikon, an ancient Thracian city ...
More News »