A team of researchers led by Andrea De Luca of the National Institute of Astrophysics in Milan studied three neutron stars dubbed PSR B0656-14, PSR B1055-52 and Geminga using the XMM-Newton satellite. The team analyzed data collected from 10 separate sections of the stars and found noticeable variations in temperature. The hot spots ranged in size from that of a football field to an area the size of an entire golf course. The temperature anomalies could be related to the stars' polar regions, the authors posit, although it remains unclear why the hot spots come in such a plethora of sizes.
"This result is a first, and a key to understand[ing] the internal structure, the dominant role of the magnetic field treading the star interior and its magnetosphere, and the complex phenomenology of neutron stars," says study co-author Patrizia Caraveo, also at the National Institute of Astrophysics. "We look forward to applying our method to many more magnetically isolated neutron stars." The work is described in the April 20 issue of the Astrophysical Journal.