NASA scientist discovers oldest white dwarf with dust rings

A NASA scientist has discovered the oldest and coldest known white dwarf - the Earth-sized remains of a dead star - ringed by dust and debris. Astronomers believe this could be the first known white dwarf with multiple dust rings.

The star, LSPM J0207+3331 or J0207, is forcing researchers to reconsider models of planetary systems that will help understand the distant future of our solar system. "This white dwarf is so old that whatever process is feeding material into its rings must operate on billion-year timescales," said John Debes, an astronomer working with the NASA-led Backyard Worlds: Planet 9 project.

"Most of the model's scientists have created to explain rings around white dwarfs only work well up to around 100 million years, so this star is really challenging our assumptions of how planetary systems evolve," Debes added.

J0207 is located around 145 light years away in the constellation Capricornus. As time passes, the white dwarfs slowly get cooler, and Debes's team calculated J0207 is about three billion years old, after monitoring the temperature level just over 5800 degrees Celsius.

J0207's ring may even be multiple rings, and the team suggests that there could be two distant components - one thin ring where the star's tides break up the asteroids and a wider ring close the white dwarf.