This newly discovered planet which orbits Alpha Centauri B, is the lightest exoplanet ever discovered in a star like our sun.
Alpha Centauri B could possibly host other planets that could be habitable.
The bright star Alpha Centauri and its surroundings
Scientists from the European Southern Observatory – ESO at La Silla say:
“This result represents a major step towards the detection of Earth twins in the immediate vicinity of the Sun.”
“Our observations extended over more than four years using the HARPS instrument and have revealed a tiny, but real, signal from a planet orbiting Alpha Centauri B every 3.2 days,” says Xavier Dumusque (Geneva Observatory, Switzerland and Centro de Astrofisica da Universidade do Porto, Portugal), lead author of the paper. “It’s an extraordinary discovery and it has pushed our technique to the limit!”
The European team detected the planet by picking up the tiny wobbles in the motion of the star Alpha Centauri B created by the gravitational pull of the orbiting planet. The effect is minute — it causes the star to move back and forth by no more than 51 centimetres per second (1.8 km/hour), about the speed of a baby crawling. This is the highest precision ever achieved using this method.
This chart shows most of the stars visible with the unaided eye on a clear night. The star Alpha Centauri is one of the brightest stars in the southern sky (marked with a red circle). It lies just 4.3 light-years from the Earth and one component in a triple star system.