Q&A: Supernova Remnants and Neutron Stars

Q:
What country has the best astronomical records of the Great Supernova of 1054 AD?

A:
That would be China. It's likely there were also Arab and European records of this spectacular event but almost none of them survived to the present.

There is a page on the creation of the Crab Nebula, which is the remnant of the supernova of 1054, at http://www.seds.org/messier/more/m001_sn.html that includes historical details.

Chandra X-ray images of the Crab may be found at: http://chandra.harvard.edu/photo/2002/0052/ Animation and videos of the Crab and other supernova at: http://chandra.harvard.edu/resources/animations/pulsar.html