Astronomers from the University of Wisconsin-Milwaukee have spotted a white dwarf type star, whose temperature is so low that it has managed to turn its carbon mass into a real diamond.
Due to the low temperature, the carbon has crystallized, thus forming a cosmic diamond the size of the Earth.
"This is a truly notable object. There must be others like it but since they are very faint it's very difficult to spot them, " says David Kaplan from the American university.
The stellar diamond was discovered using the Green Bank Telescope at the National Radio Astronomy Observatory in the US.
The white dwarf was spotted thanks to the pulsar near it. Pulsars are rapidly spinning neutron stars, whose illuminating beams are pointed toward the Earth.
According to the scientists, the pulsar near the diamond star is rotating at 30 revolutions per second. Initially, the experts thought they had found a double neutron star until they realized that the temperature of the second object was much lower than normal.
The age of the diamond dwarf is approximately equivalent to the age of the Milky Way - 11 billion years. It is located about 900 light years from Earth in the Aquarius constellation.
Researchers from the University of North Carolina add that the newly identified white dwarf is 100 times more faint than the rest of the stars around its orbit and 10 times more obscure than any star found so far.
The diamond star is composed mainly of carbon and oxygen, which have been cooling for a period of billions of years.
The white dwarf is a superdense star, whose temperature is about 4892°F (2700 °C), in contrast to the temperature of the Sun, which is about 9032°F (5000 °C).
White dwarfs are stars that collapse at the end of their life, forming objects the size of the Earth.
The first white dwarf was spotted in 1844 by the director of the Koenigsberg Observatory - Friedrich Bessel. In 1862, the Chicago Observatory confirmed the existence of these types of stars.