News

Astronomers from Durham University use prototype instrument to observe the total eclipse of the sun

(16 November 2012)

Photo: Yunnan Astronomical Observatory, Yunnan Province, China

Astronomers from Durham University used a prototype of a new instrument being developed in collaboration with a team from Yunnan Astronomical Observatory in China, to observe the outer layers of the sun during a total solar eclipse visible from northern Queensland, Australia.

The new instrument, named FASOT, is designed to measure the tangled magnetic field of the corona – the outer layer of the sun - leading to predictions of major "storms" which could affect the weather on earth and even knock out telecommunications and power distribution. 

To test it, the instrument was used to measure the spectrum of light from the corona during a total solar eclipse. These rare events occur when the moon passes in front of the sun blocking out the light from the solar disk that normally drowns out the fainter corona.

Dr Jeremy Allington-Smith, from the Centre for Advanced Instrumentation based in Durham's Physics Deparment, said:  “The prototype was able to detect traces of iron atoms in the corona which had been stripped of half of their electrons by the extreme conditions.

“This showed that a system of optical fibres, developed by Durham University, can provide detailed measurements from many parts of the sun simultaneously.

“Each of the dual array of 50 fibres is finer than a human hair and is tipped by a tiny lens to enhance performance.

He added:  “A much bigger version of the instrument is now being planned which will operate continuously without needing to wait for an eclipse.”

With minutes to go before the eclipse became total, the team was close to despair as the sun remained covered by thick cloud left over from the heavy showers of the previous days. But this moved away just in time to witness the two minutes of totality when the corona, tinged with blue and pink, was revealed in all its glory.

Dr Allington-Smith, who also worked with Durham University colleague, Dr Graham Murray, added that that the success of the prototype showed that the fibre techniques developed by Durham would greatly speed up the instrument by allowing measurements to be made over the entire face of the sun simultaneously.

The team from Yunnan Astronomical Observatory was led by Professor Zhongquan Qu and includes Dr Linhua Deng, Guangtao Dun and Liang Chang.

After checking the data, Professor Qu said that he was delighted by the measurement of the elusive highly-ionized iron atoms and could now start work on a much more ambitious system to make routine measurements of the solar magnetic field.