22 Aug 2012

Earth's end prefigured in fate of distant planet

7:15 am on 22 August 2012

Astronomers have found evidence of a planet being devoured by its star, yielding insights into the fate that will befall Earth in billions of years.

In an article published in Astrophysical Journal Letters, members of an American-Polish-Spanish research team say they discovered the evidence by looking at the chemistry of the host star.

They also think a surviving planet around this star may have been kicked into its unusual orbit by the destruction of a neighbouring world.

The BBC reports that the team made the discovery when they were studying the star BD+48 740 - one of a stellar class known as red giants. Their observations were made with the Hobby Eberly telescope, based at the McDonald Observatory in Texas.

Rising temperatures near the cores of red giants cause these elderly stars to expand in size, a process that will cause any nearby planets to be destroyed.

"A similar fate may await the inner planets in our solar system, when the Sun becomes a red giant and expands all the way out to Earth's orbit some five billion years from now," says co-author Alexander Wolszczan from Pennsylvania State University in the US.