Sheffield University Astonomer teams up with NASA

A Sheffield University astronomer has started work on a NASA mission expected to find new planets and stars similar to the sun and earth.

Professor Michael Thompson, Head of the School of Mathematics and Statistics, will lead a team looking at the interior of stars in the NASA Kepler mission which was launched on March 7th. It is expected to find about 50 earth-sized planets orbiting stars over the next three and a half years.

The Kepler Spacecraft will use its telescope to measure the variations in brightness of 170,000 stars simultaneously. If a star dims at regular intervals it indicates a potential planet crossing the path of the telescope and so orbiting the star.

Professor Thompson said: “Kepler takes things to a new dimension in terms of the number of stars we can see and information we can gather.”

The mission will also allow scientists to learn more about the stars themselves through using the asteroseismology technique – the sound of stars. Professor Thompson will play a central role in this part of the mission as he has 20 years experience studying the interior of the sun.

Sound waves travel through stars which make them oscillate or flicker. The Kepler spacecraft will record these light fluctuations over weeks, months and years to measure the exact size of the oscillations and the frequency they oscillate at.

According to Professor Thompson, a good analogy for the process is thinking of a Hi-fi speaker in a bell jar. Although you would not be able to hear the speaker, if you could see it vibrating, you would know it was making a sound. By measuring those vibrations you could work out the frequencies of the sound.

In the same way you can work out the sound of stars, despite them sitting in a vacuum.

This process will allow the team to determine the size of the stars, their chemical composition and their rotation rate.

Professor Thompson said that by characterising a star we can calculate how far away a planet can be to support the type of life forms we are familiar with.

During the first nine months in space Kepler will survey more than 5000 stars for oscillations.

Based on those measurements around 1100 stars will be followed for detailed studies throughout the mission. The accuracy at which Kepler will be able to measure oscillations is so high that the science team expects to see stars change as they age.

Professor Thompson said: “The great excitement of the work with the Kepler mission is that we’ll be able to probe the interiors of different masses and different ages, permitting us to study young suns and old suns, as well as stars that are more or less massive than our own star.”

Professor Thompson is part of a consortium of 200 researchers from 50 institutions all over the world working on the Kepler mission. Professors from Birmingham and Central Lancashire
Universities and Queen Mary College, London are also leading teams as part of the Kepler mission.

For more detailed information visit Mike Trudeau's blog for an excellent analysis.