[extropy-chat] Diamonds are forever

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Biggest diamond out of this world
Stephen Cauchi, The Age 18 Feb 2003

Confirming what the Beatles always knew, astronomers have actually found a
diamond in the sky - directly above Australia. It is the biggest known
diamond in the universe, in fact. According to American astronomers at the
Harvard-Smithsonian Centre for Astrophysics, a white dwarf star in the
constellation of Centaurus, next to the Southern Cross, has been found to
have a 3000-kilometre-wide core of crystallised carbon, or diamond. It
weighs 2.27 thousand trillion trillion tonnes - that's 10 billion trillion
trillion carats, or a 1 followed by 34 zeroes. The biggest earthly jewel is
one of the British crown jewels, the 530-carat Star of Africa.
However, this cosmic jewel is hidden beneath a layer of hydrogen and helium
gases, with the diamond core making up between 50 and 90 per cent of its
mass. "It's the mother of all diamonds," said astronomer Travis Metcalfe,
who led the team of researchers that studied the star. "Some people refer to
it as Lucy, in a tribute to the Beatles song Lucy in the Sky with Diamonds."
Known officially as BPM 37093, the star confirms a theory, first raised in
the early 1960s, that cool white dwarfs should have a diamond core. A white
dwarf is what small stars, those up to about the size of the sun, turn into
when they run out of nuclear fuel and die. The intense pressures at the
heart of such dead stars compress the carbon into diamond. But confirming
this theory has only been possible recently. Lucy "pulsates", which means
its light fluctuates at regular intervals. "By measuring these pulsations,
we were able to study the hidden interior of the white dwarf, just like
seismograph measurements of earthquakes allow geologists to study the
interior of the Earth," Dr Metcalfe said. "We figured that the carbon
interior of this white dwarf has solidified to form the galaxy's largest
diamond." This means that other white dwarfs must also have diamond cores.
Our own sun will become a white dwarf when it dies in 5 billion years. Two
billion years after that, its ember core will crystallise as well, leaving a
giant diamond in the centre of our solar system. Vince Ford, a research
officer at Mount Stromlo Observatory near Canberra, said astronomers,
including Australians, had observed the star for more than eight years. The
star is about 50 light years away (500 trillion kilometres) - a fair
distance as far as stars go. This means it is about 400 times too faint to
see with the naked eye.

[? not sure 50 light years is that far with the Milky Way's diameter c.
100,000 light years - Avatar
Perhaps a controlled process could lead to using the star diamond as a kind
of chip...]