Astronomers find oldest known star

International astronomers say they have found the oldest known star encircled by five Earth-sized planets, signaling that planets formed throughout the history of the universe.

The system is 11.2 billion years old and was born near the dawn of the galaxy, said the report in the Astrophysical Journal.

The star has been named Kepler-444, as it was found with the help of NASA's planet-hunting Kepler spacecraft, which was launched in 2009.