Long after the fusion faded and its furnaces cooled down, the grill of our sun in the sky will form a huge crystal – one of the countless sprinkled on our galaxy.
Astronomers have found evidence that massive white dwarf stars star into metal crystals early in retirement. In addition to poetic descriptions, I could challenge how we calculate the age of some of the oldest objects in space.
Researchers from the United Kingdom, Canada, and the United States have come up with support from the Gaia European Space Agency's satellite data support for a 50-year hypothesis that describes the stages through which many stars pass before they end their lives like crystals.
"This is the first direct evidence that white dwarfs crystallize or pass from fluid to solid," says physicist Pier-Emmanuel Tremblay of the University of Warwick.
"Fifty years ago, it was anticipated that there would have been an accumulation of the number of white sticks in certain brightness and colors due to crystallization, and it was only now that it was observed."
While huge stars, which are much larger than ours, go with a bang, most of the sun in space has a pretty average mass that they see more quietly.
When hydrogen runs out, stars like our Sun begin to cool down and shrink. This provides a brief, rising energy that bursts into the atmosphere in enormous proportions and thus sends out a lot of its heat.
Meanwhile, its core continues to shrink and put helium into even more difficult elements, such as carbon and oxygen.
The end result is white dwarfs – large eggs, so dense, small 1 cm3 its part would weigh about 10 tons.
The ultimate fate of these warm hearts of dying stars will eventually be a frozen body, called a black dwarf.
Depending on how long it takes for white dwarfs to cool off, few (if any) should reach this point. Finding one would deeply change how we thought about the age of the universe.
But how does the white dwarf get lost? Internal mechanics is a big difference in how heat penetrates the surface and has long been debated.
Deep in the white dwarf, its electrons move freely, they slip through a jiggling set of carbon and oxygen nuclei and slowly transmit heat to a more conductive surface.
In theory, at about 10 million degrees, there is no longer enough energy to move positive nuclei in the core from the position. They lock in place and form an extensive crystal structure that liberates a lot of energy.
The question is all a matter of time. In small white dwarfs, crystallization coincides with a process that connects the core to the outer layers, which allows heat energy to be easily lost. Once the star is connected, it cools quite effectively.
Many heavier stars are more secretive. Finding evidence of their own sequence was difficult, due to the small size of the white dwarfs in general, and because of the less obvious cooling sign of the larger varieties.
Researchers have collected data on more than 15,000 objects, which are probably white dwarfs, all in approximately 300 light-years of the Earth. When comparing their masses and ages, they found that there are several stars, as the light and color should be determined.
This pattern coincided nicely with theoretical predictions describing how the white dwarfs of a given mass emit heat, indicating that crystallization occurs much earlier in white dots with masses that exceed our sun.
"All white dwarves will once crystallize in their evolution, although more massive white dwarfs go through the process earlier," says Tremblay.
"This means that billions of white dots in our galaxy have already completed the process and are essentially crystalline spheres in the sky."
The confirmation of this model has some very big consequences for the aging of some of the most common buildings in Rimska cesta.
By crystallization that occurs before white canes emit this heat, their cooling process is impeded, which slows down their aging process by up to 2 billion years.
Not only did the researchers find that crystallization was already in the beginning of heavy white dots, but there was significantly more energy than expected, lost when this heat was released.
"We believe that this is initially due to the crystallization of oxygen and then immersion into the core, a process similar to sedimentation on the riverbed on Earth," says Tremblay.
This observation provides astronomers with observations that can help confirm how stars, like our sun, change over time and give us a much better idea of the evolution of our galaxy.
The rest can be seen in the cosmos and we appreciate the flames of stardust furnaces, even more gems than we ever imagined.
This research was published in Ljubljana Nature.