Thousands of stars turning into crystals

White dwarf star in the process of solidifying

White dwarf star in the process of solidifying. Credit Dr Mark A. Garlick

The substances that make out the crystal spheres are oxygen and carbon which under such a high density make the stars look like metal.

Dr Tremblay said: 'This is the first direct evidence that white dwarfs crystallise, or transition from liquid to solid.

And there are billions of similar sparkling crystal spheres in the Milky Way alone.

Dr. Pier-Emmanuel Tremblay from the University of Warwick's Department of Physics said, "This is the first direct evidence that white dwarfs crystallize, or transition from liquid to solid".

When that process comes to an end, the sun will enter the white dwarf stage, which is essentially a retired star made up primarily of oxygen and carbon gas.

This process of solidification, or crystallisation, of the material inside white dwarfs was predicted 50 years ago but it wasn't until the arrival of Gaia that astronomers were able to observe enough of these objects with such a precision to see the pattern revealing this process.

White dwarf stars are already some of the oldest star stuff in the universe. But I still wouldn't mind skipping the part where our entire planet is swallowed in the hellacious heat of a massive nuclear furnace we once called the sun. But when the Sun dies, it will turn into an enormous crystal ball, according to a new study.

Cancer mortality milestone: 25 years of continuous decline
Meanwhile, some cancers that have been linked to obesity, including liver and pancreatic, showed signs of an increase. Although the racial gap in cancer deaths is slowly narrowing, socioeconomic inequalities are widening.

Many scientists thought it was likely that white dwarf stars would form crystals as they cooled, but there was disagreement about whether the energy released from the process would be detectable, Tremblay said.

They identified a pile-up, an excess in the number of stars at specific colours and luminosities that do not correspond to any single mass or age.

Scientists trained the Gaia space telescope on 15,000 white dwarf candidates within around 300 light years of Earth. Analyzing the Gaia data, Tremblay et al found a pile-up of white dwarfs of certain colors and luminosities (highlighted with orange lines) that were otherwise not linked together in terms of their evolution.

The core will become a tiny white dwarf star. Image credit: Tremblay et al, doi: 10.1038/s41586-018-0791-x.

"We will now have to develop better crystallisation models to get more accurate estimates of the ages of these systems". They are the rest of the centers of red goliaths after these colossal stars have passed on and shed their external layers and are always cooling as they discharge their accumulated warmth through the span of billions of years.

But just as the water in your freezer continues to cool after it releases all its latent energy, white dwarfs eventually resume their cooling as well.

"All white dwarfs will crystallise at some point in their evolution, although more massive white dwarfs go through the process sooner".

Latest News