The ESO finds an exoplanet in orbit around Alpha Centauri b – the closest exoplanet found to our Solar System.
Published in the journal Nature, a team from the European Southern Observatory has discovered an exoplanet in orbit around Alpha Centauri b that is among the lightest exoplanets ever discovered.
Discovered using the HARPS spectrograph instrument on the 3.6m ESO Telescope using observations over a period of about 4 years, the new planet has a mass barely more than that of Earth – only enough to move its “parent” star back and forth by no more than 51cm.
Finding the planet is significant since Earth-mass planets in the habitable zone around stars are very difficult to detect since planets are swamped by data from the parent star. By finding this planet the team have a significant milestone achievement: demonstrating the radial-velocity technique is a viable method for detecting exoplanets similar to Earth orbiting stars similar to, or colder than, our own Sun.
Previous studies have shown that is statistically likely that there are more exoplanets around Alpha Centauri B, as small-mass planets are preferentially created in multiple-planet systems.
The paper submitted to to Nature: “An Earth Mass Planet orbiting Alpha Centauri B” – Xavier Dumusque, Francesco Pepe, Christophe Lovis, Damien Ségransan, Johannes Sahlmann, Willy Benz, François Bouchy, Michel Mayor, Didier Queloz, Nuno Santos and Stéphane Udry.