The Largest Diamond ( a star )

BBC
Monday, 16 February 2004

Diamond star thrills astronomers
Concept image (Harvard-Smithsonian Center for Astrophysics)

A diamond that is almost forever

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.

(more at link...)

http://news.bbc.co.uk/1/hi/3492919.stm

So, they have calculated using math in theories that some measurement could mean that there is a solid carbon core inside a dwarf star.
1) how is this a direct evidence? I can do the same and discover a planet with flying donkeys.
2) I hope Metcalfe is not a physicist, because assuming a random dwarf is the largest diamond in the galaxy ignoring all the other billions of possible dwarf-star diamonds is extremely un-intelligent.
3) I first understood that the star died and that caused the carbon to solidify and crystallize, but I was wrong! They really believe that a working star can have a diamond core, and still being capable of all the magic nuclear fusion and stuff?

But thank you, journalist, for telling us all that we have a huge diamond in our galaxy, now maybe they can shut the funding and let the physicists collect it and become self sufficient.

It's only 50 light-years away, and yet humanity's "amazing" and "incredibly accurate" telescopes can't photograph it. But every other year it's a new story about capturing the universe's oldest star or the largest star or the most neutronified neutron star or... Or...

Salesmanship sans science.