Advantages of Neutron Stars

One key advantage that neutron stars have over black holes is that their surface is visible to us, enabling much to be be learned about their atmospheres and interior structure. 

In 2009, researchers found evidence for a carbon atmosphere on the neutron star in the Cassiopeia A supernova remnant, using NASA's Chandra X-ray Observatory

Figure. The remarkable properties of the carbon atmosphere on the neutron star in the Cassiopeia A supernova remnant.

• It is only about four inches thick and has a density similar to diamond and a pressure more than ten times that found at the center of the Earth .
• As with the Earth's atmosphere, the extent of an atmosphere on a neutron star is proportional to the atmospheric temperature and inversely proportional to the surface gravity. 
• The temperature is estimated to be almost two million degrees, much hotter than the Earth's atmosphere. 
• The surface gravity on Cassiopeia A is 100 billion times stronger than on Earth, resulting in an incredibly thin atmosphere