Astronomers spot white dwarf star with two rings of planetary debris

By Will Dunham WASHINGTON, Nov 7 (Reuters) – Billions of years from now, the sun is expected to run out of fuel and greatly expand into what is called a red giant, eventually shedding its outer layers and leaving behind its dense core, a white dwarf. Some of the planets in our solar system would be destroyed while others might survive. Researchers have now spotted a white dwarf with planetary…