One of the largest known diamonds in the universe has been spotted by an international team of astronomers working through the Virginia-based National Radio Astronomy Observatory.
The Earth-sized ball of crystallized carbon -- which essentially qualifies as a diamond -- is located approximately 900 light-years away in the direction of the constellation Aquarius and has been identified as the coldest, faintest white dwarf star ever detected.
Findings from the new research are published in the Astrophysical Journal.
"It's a really remarkable object," David Kaplan, a professor at the University of Wisconsin-Milwaukee, said in an NRAO news release. "These things should be out there, but because they are so dim they are very hard to find."
Kaplan and his fellow researchers discovered the white dwarf using the The NRAO's Green Bank Telescope in West Virginia, the Very Long Baseline Array, a network of 10 radio telescopes situated across the globe, and other observatories.
White dwarfs are stars in their end-states that have collapsed to form extremely dense objects roughly the size of the Earth.
Composed predominantly of carbon and oxygen, white dwarfs cool slowly, fading during a span of billions of years.
The newly-found white dwarf gem -- located via the radio emissions of its companion pulsar, the rapidly-spinning remains of a massive star that went supernova sometime in the past -- is estimated to be round 11 billion years old, the same approximate age as the Milky Way galaxy.
Bart Dunlap, a graduate student at the University of North Carolina at Chapel Hill and one of the research team members, explains observations of the pulsar, designated PSR J2222-0137, strongly suggest the presence of the white dwarf diamond, since the strongest telescopes in the world still haven't actually imaged the gigantic gem.
"Our final image should show us a companion one hundred times fainter than any other white dwarf orbiting a neutron star and about ten times fainter than any known white dwarf, but we don't see a thing," Dunlap said "If there's a white dwarf there, and there almost certainly is, it must be extremely cold."
The researchers believe the white dwarf's core burns at no more than 3,000 degrees Kelvin, or 2,700 degrees Celsius, which is about 4,800 degrees Fahrenheit. As a comparison, our own sun is a toasty 5,000 times hotter at its center.
Therefore, astronomers believe that such a collapsed, relatively cool star would be largely crystallized carbon, not unlike a diamond.