26 Jun 2013

New planets discovered 22 light years from Earth

9:11 pm on 26 June 2013

An international team of astronomers has discovered a group of planets 22 light years from Earth.

The three planets, known as super earths, circle a star called Gliese 667C and are part of a group of at least seven.

It's the first time that astronomers have observed so many planets in an orbit that might support life. They believe the planets may be rocky and have water on their surfaces.

Astronomers led by Guillem Anglada-Escude of the University of Gottingen, Germany, and Mikko Tuomi, of the University of Hertfordshire, Britain, used a suite of telescopes including the 3.6 metre telescope at the Silla Observatory in Chile.

Gliese 667C is a low-luminosity "M-dwarf" star just over one-third the mass of our Sun.

The BBC science correspondent said the team is confident that three rocky worlds occupy this region at Gilese 667C.

"Their estimated masses range from 2.7 to 3.8 that of the Earth's," Dr Tuomi told BBC News.

"However, we can only estimate the physical sizes by assuming certain compositions that is, well, only educated guessing.

"Their orbital periods are 28, 39, and 62 days, which means that they all orbit the star closer to its surface than Mercury in our own system.

''Yet the estimated surface temperatures enable the existence of liquid water on them because of the low luminosity and low mass of the star."