In about 10 billion years, our sun is likely to turn into a white dwarf — a shrunken, extremely dense star whose nuclear core has burned out and gotten rid of its outer layers.
A new study published Wednesday in the journal Nature claims to reveal the first evidence that white dwarf stars form solid, crystal cores containing metallic oxygen and carbon. The oldest white dwarfs, the study finds, are likely to be almost fully comprised of crystals.
Why it matters: The process of crystallization, similar to water turning into ice but occurring at far higher temperatures (about 10 million degrees Celsius), slows the cooling of these stars, potentially making them billions of years older than originally thought. Scientists use white dwarfs as markers of time in order to get a better idea of the age of surrounding stars and planets.
What they did: Astronomers from the University of Warwick in the U.K. used observations from the European Space Agency's Gaia satellite to examine the luminosities and colors from about 15,000 white dwarf candidates within about 300 light-years of Earth.
- They found a large number of stars that had colors and luminosities that seemed to match the phase in a star's development when it's releasing huge amounts of latent heat, which results in a slower cooling process.
- According to a press release, such stars may have slowed their aging by as many as 2 billion years.
"This means that billions of white dwarfs in our galaxy have already completed the process and are essentially crystal spheres in the sky."— Study lead author, astronomer Pier-Emmanuel Tremblay, in a statement