The latest discovery of a planet orbiting another star has delighted astronomers because it suggests they might in future spot worlds as small as the Earth.
The new find is another giant planet, nearly twice as wide as Jupiter, and is the first discovery by the Corot satellite launched by Europe on December 27 last year to seek out new worlds.
It comes just days after another team of astronomers reported finding the first Earth-like planet beyond the solar system.
As well as spotting the new planet, Corot was able to measure the first starquakes – ripples of seismic activity within a star.
What has the scientists excited is the unexpected accuracy of Corot’s measurements. It leads them to believe that they will not only be able to detect small rocky planets but also tell what sort of rocks are made of – i.e. their chemical composition.
The new planet, labelled Corot-Exo-1b, zips around a Sun-like star in just a day and a half, making it another of the now familiar “hot Jupiters” that appear to be abundant in other solar systems. It was detected during a so-called transit when it passed in front of the star, causing a slight dimming of its light.
The planet lies around 1,500 light-years from Earth in the constellation of Monoceros, the Unicorn. The margin of error in the data is so tiny that it means planets as small as Earth could be spotted by Corot – that is three times smaller than initially thought possible. If the satellite is able to detect subtle variations in the star’s light reflected by the planet, it will indicate its chemical make-up.
The starquake data was recorded by observing a star continuously for 50 days and is so accurate that the margin of error of is less than one part per million. The star showed large, unexpected luminosity variations on time scales of a few days, which may be related to the star’s magnetic activity.
Malcolm Fridlund, Corot Project Scientist for the European Space Agency, said: “The data we are presenting is still raw but exceptional. It shows that the on-board systems are working better than expected in some cases – up to ten times the expectation before launch. This will have an enormous impact on the results of the mission. Having seen its quality, we can expect great discoveries in the future.”