November 15, 2012
Astronomers Capture Prophesy Of Our Own Solar System’s Fate
Lee Rannals for redOrbit.com - Your Universe Online
Astronomers recently found evidence for a dying star coming back to life, giving insight into what may be the fate of our own Solar System in a few billion years.
The picture released by the European Space Agency (ESA) is of the planetary nebula Abell 30, located 5,500 light-years away from Earth.
A planetary nebula is the often-concentric shells of stellar material cast into space by dying stars. Astronomers in the 18th century thought these objects looked like the colorful "blob" of a planet, giving them the name planetary nebula.
A star with less than eight times the mass of the Sun swells into a red giant towards the end of its life, and its outer layers are expelled through pulsations and winds.
ESA said ultraviolet radiation shining out from the stripped-down hot stellar core begins to light up the ejected shells, which results in the beautiful imagery that can be captured by telescopes.
"The star at the heart of Abell 30 experienced its first brush with death 12 500 years ago — as seen from Earth — when its outer shell was stripped off by a slow and dense stellar wind," according to a prepared statement from ESA.
Telescopes see the remnant of this evolutionary stage as a large, near-spherical shell of glowing material that expands out into space.
About 850 years ago, ESA said the star suddenly came back to life, coughing out helium and carbon-rich material in a violent event.
The star's outer envelope expanded during this born-again phase, but then very rapidly contracted again within 20 years. This made the wind from the star jump to 8 million mph.
As the stellar wind starts to catch up and interact with the slower wind, clumps of previously ejected material start forming complex structures.
"The stellar wind bombarding dense clumps of material provides a chilling look at the possible fate of Earth and its fellow planets in our own Solar System in a few billion years´ time," ESA said.
According to the space agency, once our Sun emits its final breath of life, its strong stellar wind and harsh radiation will evaporate any planets that may have survived the red giant phase of stellar evolution.