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. It is also the lightest exoplanet ever discovered around a star like the Sun.
With an orbital period estimated to be just 3.2 days, the planet in orbit around Alpha Centauri B is too close to its sun to be habitable. But finding it validates earlier calculations that planets can exist in stable orbits within the habitable zones of the two Sun-like stars in the Alpha Centauri system.
The research paper detailing the discovery is to be published in the journal Nature today, 17 October 2012.
One estimate is that it would take about 85 years to reach the Alpha Centauri system using an as yet to be developed nuclear pulse propulsion system.
When I first read this I couldn’t help but think, “Man this sounds a lot like Helliconia!” (Brian Aldiss’s fictional planet Helliconia orbits a yellow-orange G class star called Batalix, but has to endure a scorching every two millenia on the close approach of its A class companion Freyr — maybe the ISO would consider naming this new planet Helliconia once it’s confirmed).