Scientists have created the first "hotspot" map of the surface of a strange star, thanks to a telescope on the International Space Station.
First Map of a Pulsar's Surface Reveals 'Hotspots' in Unexpected Places : Read more
"Through independent measurements of J0030, these teams also arrived at similar results for the pulsar's mass and size: Riley's team determined that the pulsar is roughly 1.3 times the mass of the sun and 15.8 miles (25.4 kilometers) in diameter, while Miller's team estimated that J0030 is 1.4 times the mass of the sun and about 16.2 miles (26 km) in diameter."
Very interesting. The mean density must be some 3E+14 g cm^-3 so very dense. Looks like a good target for viewing and testing aspects of General Relativity description of gravity.