Thought this would be fun for everyone to read… Jeanne
Diamond star thrills astronomers
Twinkling in the sky is a diamond star of 10 billion trillion
trillion carats, astronomers have discovered.
The cosmic diamond is a chunk of crystallised carbon, 4,000 km
across, some 50 light-years from the Earth in the
constellation Centaurus.
It’s the compressed heart of an old star that was once bright
like our Sun but has since faded and shrunk.
Astronomers have decided to call the star “Lucy” after the
Beatles song, Lucy in the Sky with Diamonds.
Twinkle twinkle
“You would need a jeweller’s loupe the size of the Sun to
grade this diamond,” says astronomer Travis Metcalfe, of the
Harvard-Smithsonian Center for Astrophysics, who led the team
of researchers that discovered it.
The diamond star completely outclasses the largest diamond on
Earth, the 546-carat Golden Jubilee which was cut from a stone
brought out of the Premier mine in South Africa.
The huge cosmic diamond - technically known as BPM 37093 - is
actually a crystallised white dwarf. A white dwarf is the hot
core of a star, left over after the star uses up its nuclear
fuel and dies. It is made mostly of carbon.
For more than four decades, astronomers have thought that the
interiors of white dwarfs crystallised, but obtaining direct
evidence became possible only recently.
The white dwarf is not only radiant but also rings like a
gigantic gong, undergoing constant pulsations.
"By measuring those 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.
“We figured out that the carbon interior of this white dwarf
has solidified to form the galaxy’s largest diamond,” says
Metcalfe.
Astronomers expect our Sun will become a white dwarf when it
dies 5 billion years from now. Some two billion years after
that, the Sun’s ember core will crystallise as well, leaving a
giant diamond in the centre of the solar system.
“Our Sun will become a diamond that truly is forever,” says
Metcalfe.