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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

Go deeper

39 mins ago - Politics & Policy

Biden's latest executive order: Buy American

President Joe R. Biden speaks about the economy before signing executive orders in the State Dining Room at the White House on Friday, Jan 22, 2021 in Washington, DC. (Photo by Jabin Botsford/The Washington Post via Getty Images)

President Joe Biden will continue his flurry of executive orders on Monday, signing a new directive to require the federal government to “buy American” for products and services.

Why it matters: The executive action is yet another attempt by Biden to accomplish goals administratively without waiting for the backing of Congress. The new order echoes Biden's $400 billion campaign pledge to increase government purchases of American goods.

Tech digs in for long domestic terror fight

Illustration: Sarah Grillo/Axios

With domestic extremist networks scrambling to regroup online, experts fear the next attack could come from a radicalized individual — much harder than coordinated mass events for law enforcement and platforms to detect or deter.

The big picture: Companies like Facebook and Twitter stepped up enforcement and their conversations with law enforcement ahead of Inauguration Day. But they'll be tested as the threat rises that impatient lone-wolf attackers will lash out.

The pandemic could be worsening childhood obesity

Illustration: Aïda Amer/Axios

The 10-month long school closures and the coronavirus pandemic are expected to have a big impact on childhood obesity rates.

Why it matters: About one in five children are obese in the U.S. — an all-time high — with worsening obesity rates across income and racial and ethnic groups, data from the National Health and Nutrition Examination Survey show.