European orbiting X-ray observatory gives new insight into neutron stars
The orbiting X-ray observatory, XMM-Newton, has given astronomers and physics a valuable new insight into the most exotic stars in the Universe: neutron stars. Whilst the composition of these extremely dense stellar objects has proved to be a bit of a puzzle for astronomers, now two researchers from the Centre d'Etude Spatiale des Rayonnements in Toulouse, France, have found that neutron stars almost certainly resemble over-sized atomic nuclei and are most likely to be composed of neutrons. Employing XMM-Newton's EPIC camera, the researchers were able to find three previously undiscovered neutron stars and accurately measure the quantity of various X-rays coming from their surfaces. The two scientists were then able to compare their results with theoretical predictions to deduce the internal composition of these neutron stars, which are the remains of exploded stars. Using new computer codes, they found that astronomers had previously been under-estimating the mass and over-estimating the radii of some neutron stars. They also discovered that after all the musing over highly complicated particle interiors, the most likely composition of a neutron star is still what astronomers suspected 40 years ago: neutrons. They found only one exotic solution that remained feasible, an interior made of quarks. These particles are constituents of neutrons and would be able to squeeze together more densely. Now they hope to extend their work to other neuton stars.