Scientists have discovered a star that is in the process of crystallizing into a celestial diamond. The star is a white dwarf, the shrunken shell of a sun-like star that consumes most of its fuel before it collapses. For stars whose cores are mostly composed of metallic oxygen and carbon, the cooling process following the collapse of the white dwarf will eventually cause the star to crystallize into a giant diamond.

But this process is so slow that researchers don’t think any star in the universe has actually become a huge, shiny ball; Scientists have calculated that such a transition would take a quadrillion years, and that the universe is only 13.6 billion years old. (A quadrillion is a thousand trillion, and a trillion is a thousand billion.)

However, researchers now believe they have found a star that is in the early stages of this transit. The star, HD 190412 C, is about 104 light-years away in a quadruple star system called HD 190412. The researchers calculated the star’s temperature to be about 11,420 degrees Fahrenheit (6,300 degrees Celsius), which puts it in the crystallization range. Because there are other stars in the white dwarf system that have not yet collapsed to white dwarf status, the researchers were able to use the composition of these still-burning stars to determine how much metal is in the white dwarf’s core. They also estimated the age of the star to be about 4.2 billion years.

Also, knowing the exact distance of the star system from Earth is key to calculations, as distance affects the brightness of light from the dim white dwarf. The researchers used data from the European Space Agency’s Gaia mission, which aims to create a 3-D map of one billion stars in the Milky Way.

Using this information, the team modeled the cooling of a white dwarf over time and confirmed the first case of crystallization of a white dwarf of known age. As there are other systems similar to HD 190412, including the star system home to the bright star Sirius, the researchers report that there may be other crystallizing white dwarfs nearby in the cosmic neighborhood. Source