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UK astronomers celebrate discovery of new Earth-sized planet
European astronomers have discovered a planet with about the mass of the Earth orbiting a star in the Alpha Centauri system — the nearest to Earth at only 4.3 light-years away. This result represents a major step towards the detection of a twin Earth in the immediate vicinity of the Sun – the Holy Grail of astronomy.
Leading British astronomers working in this research field have described this discovery as a fantastic result and a major step in the future detection of Earth-like planets.
Professor Don Pollacco from the Astronomy and Astrophysics Group at University of Warwick said: “We think planets form in the debris left over from the formation of their stars. This discovery shows that, if we look hard enough, we're likely to find planets everywhere. These fantastic results show that to reveal the signal of such a low mass planet, not only do you need dedicated (but modest) facilities, but that understanding the normal phenomena occurring in stars is important. Here observations were obtained over many years that allow the magnetic cycle of the star (like the sunspot cycle on the sun) and its rotation period to be accounted for allowing the weak
planetary signal to be detected”.
Professor Isabelle Baraffe, Head of the Astrophysics group, CEMPS at the University of Exeter said: "This is an absolutely fantastic result. The Holy Grail is to find the twin of the earth which means having a planet with the mass of the earth orbiting a sun and in a habitable zone which would favour the presence of liquid water and therefore we think would favour the presence of life. The discovery of this planet is the first step towards this Holy Grail. Of course this is not in the habitable zone as it's very close to its star - the same distance that mercury sits from our sun, so the conditions are burning at the surface of the planet. It does tell us, however, that the Alpha Centauri system has other planets. As it is unthinkable that there would be one planet in isolation, this star is a gold mine for the detection of planets".
Dr Suzanne Aigrain from the University of Oxford said: "This is a very exciting result, because the star is so near and the planetary signal is so small. It represents a major step forwards in understanding and mitigating the effects of stellar activity, which will be crucial for the detection of increasingly Earth-like planets."
Andrew Cameron, Professor of Astronomy at the University of St Andrews said: “This is yet another demonstration of the exquisite capability of the HARPS and HARPS-North spectrographs to measure the masses of very small planets orbiting distant stars. In the future, it will be important to combine measurements of this kind with the transit method, so we can measure their diameters as well as their masses. If we can determine their bulk composition, we will learn something about their formation history, water content and atmospheres”.
The planet, the lightest ever discovered around a star like the Sun, was detected using the HARPS instrument on the 3.6-metre telescope at European Southern Observatory’s (ESO) La Silla Observatory in Chile.
The Science and Technology Facilities Council manages the UK subscription to ESO.
The full ESO release can be read here (link opens in a new window) (link opens in a new window).
Contacts
To speak with any of these UK astronomers please contact:
Lucy Stone
Press Officer
STFC
Tel. 01235 445627/07920 870125
E-mail: lucy.stone@stfc.ac.uk
Professor Andrew Cameron – University of St. Andrews
Dr Suzanne Aigrain – University of Oxford
Don Pollacco – University of Warwick
Prof. Isabelle Baraffe - Head of Astrophysics group, University of Exeter
Notes
More information
This research was presented in a paper “An Earth mass planet orbiting Alpha Centauri B”, to appear online in the journal Nature on 17 October 2012.
The year 2012 marks the 50th anniversary of the founding of the European Southern Observatory (ESO). ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research.
ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.
