Hi David;
Yes .. this news is everywhere this morning .. even on the radio news!
Good work with base observations from the Parkes Radio Telescope headed up by an Aussie Astronomer !
I notice that the conclusion of 'diamond' is based on the assumption that the planet was formerly a white dwarf in the binary pair .. I can't find anywhere, any measured evidence for this, (although that's probably not surprising .. carbon is the most likely core substance, I guess).
Because of its proximity to the neutron, and because its not losing mass, it has to be incredibly dense (at least 23g/cm^3 .. probably more). Hence the conclusion of compressed carbon .. diamond.
Very interesting. Thanks for the post.
Cheers
PS:
Here's the animation produced by Matthew Bailes, himself !