A group of European astronomers has just discovered a planet of similar mass to Earth orbiting a star in the Alpha Centauri system, which is also the closest of these characteristics ever discovered. To achieve this finding, the researchers used the HARPS instrument installed at the La Silla Observatory of the European Southern Observatory (ESO).
“Our observations lasted for more than four years, using the HARPS instrument, and have revealed a tiny but real signal that shows a planet orbiting Alpha Centauri B every 3.2 days”, explained Xavier Dumusque of the Geneva Observatory, Switzerland, and Center for Astrophysics of the University of Porto, Portugal and main author of the article. To which he pointed out that “it is an extraordinary discovery and has taken our technology to its limits!” But what is special about this discovery?
Alpha Centauri is the closest star system to our planet, located about 4.3 light years away. In addition, this triple star system composed of two stars similar to the sun orbiting close to each other, is one of the brightest in the southern skies. This closeness to our planet is basic to the importance of the find, since it is the closest planet with characteristics similar to those of the Earth ever found.
Yet despite its resemblance to Earth, it hardly harbors life. In the words of Stephane Udry, co-author of the paper and belonging to the Geneva Observatory, ” this is the first planet with a mass similar to that of the Earth found around a Sun-type star . It orbits very close to its star and must do too heat to house life as we know it. ” Furthermore, according to the same researcher, “it is possible that it is part of a system in which there are more planets . Other results from HARPS and new discoveries by Kepler clearly show that most of the low-mass planets are found in this type of planets. systems “.
And it is that since the first exoplanet orbiting a Sun-like star was discovered in 1995, the findings have not stopped happening. More than 800 exoplanets have been confirmed, but most are larger than Earth and more like Jupiter. As Xavier Dumusque himself explains, ” This result represents a great step forward towards the detection of a twin planet to Earth in the immediate vicinity of the Sun. We are living in exciting times!”
