Astronomers discover oldest known star with 5 Earth-like planets

Astronomers have recently observed a star that is 11.2 billion years old and has at least five Earth-size planets.

The newly discovered solar system which consists of the oldest star with Earth-size planets ever found proved that such planets have formed throughout the history of the universe.

The star, named Kepler-444, hosts five planets smaller than Earth, with sizes varying between those of Mercury and Venus.

The international team of astronomers used observations made by NASA's Kepler satellite. The scientific collaboration was led by the University of Birmingham and contributed to by the University of Sydney.

Together with their international colleagues the university's astronomy team used asteroseismology to determine the age of the star and planets. This technique measures oscillations, the natural resonances of the host star caused by sound waves trapped within it.

Dr. Daniel Huber from the University's School of Physics said that in the case of Kepler-444 the planets orbit their parent star in less than 10 days, at less than one-tenth the Earth's distance from the Sun, so their closeness to their host star means they are uninhabitable because of the lack of liquid water and high levels of radiation.

The study is published in the Astrophysical Journal.