Alpha Centauri Bb – planetaria

Artist’s conception of the Alpha Centauri binary star system and the exoplanet Alpha Centauri Bb. Our own Sun is also shown in the distance. Image Credit: ESO/L. Calçada/N. Risinger

The closest star system to our own Sun may have two Earth-sized exoplanets orbiting it, a new study has shown based on observations by the Hubble Space Telescope. If confirmed, the discovery would help to illustrate just how common exoplanets are; data from Kepler and other telescopes has also already shown that the vast majority of stars have exoplanets orbiting them, and the number of exoplanets in our galaxy alone is now thought to number in the billions.