Astronomers have discovered the first exoplanet orbiting a star almost identical to the Sun.
Astronomers have used ESO’s HARPS planet hunter in Chile, along with other telescopes around the world, to discover three planets orbiting stars in the cluster Messier 67. Although more than one thousand planets outside the Solar System are now confirmed, only a handful have been found in star clusters. Remarkably one of these new exoplanets is orbiting a star that is a rare solar twin — a star that is almost identical to the Sun in all respects.
This discovery is interesting in that some astronomers have proposed that our Sun itself was born in M67, the open galactic star cluster where these exoplanets were found. My March 2012 cover story for Sky & Telescope was on this very subject.