Billions of years in the future, our dead sun will morph into a giant cosmic jewel, a new study suggests.
Like the vast majority of stars in our Milky Way galaxy, the sun will eventually collapse into a white dwarf, an exotic object about 200,000 times denser than Earth. To put that in perspective: A mere teaspoon of white-dwarf material would weigh about as much as an elephant, if you could somehow transport the stuff to our planet.
Half a century ago, theorists predicted that white dwarfs solidify into crystal over time — and the new research has found that this is indeed the case.
All white dwarfs will crystallize at some point in their evolution, although more massive white dwarfs go through the process sooner," study lead author Pier-Emmanuel Tremblay, a physicist at the University of Warwick in England, said in a statement.
"This means that billions of white dwarfs in our galaxy have already completed the process and are essentially crystal spheres in the sky," Tremblay added. "The sun itself will become a crystal white dwarf in about 10 billion years."
Tremblay and his colleagues analyzed data gathered by the European Space Agency's Gaia spacecraft, which launched in December 2013 to help researchers construct the best-ever 3D map of the Milky Way. Gaia does this by precisely monitoring the positions of huge numbers of stars; the mission team aims to study 1 billion stars over the spacecraft's operational lifetime.
For the new study, the researchers looked at Gaia measurements of about 15,000 white dwarfs, all of which lie within 330 light-years of the sun. These data revealed an odd "pileup" — an overabundance of white dwarfs with certain colors and brightnesses that cannot be explained by the objects' ages or masses.