The study of the properties of light using the Very Large Telescope (VLT) of the European Southern Observatory has led astronomers to quite unexpected results. It turned out that the polarization of light around the observed neutron star indicates the presence of a quantum effect, which scientists predicted back in the 1930s, calling it double refraction of rays in a vacuum.
The discovery was made by a group of researchers led by Roberto Mignani from the National Astrophysical Institute (Istituto Nazionale di Astrofisica, INAF) in Italy. Scientists have made a detailed analysis of the VLT data from observations of the star, code-named RX J1856.5-3754, located 400 light years from Earth. The research was submitted to the Monthly Notices of the Royal Astronomical Society.
Neutron stars are thought to be the very dense cores of massive stars with a mass at least 10 times that of the Sun. The stars received this status after certain dramatic events at the end of their life cycle, namely a supernova explosion. Such objects have extremely powerful magnetic fields, their power is billions of times greater than the power of the Sun's magnetic field. Due to this, they are able to influence the empty space surrounding the star.
According to the laws of physics, when passing through a vacuum, light passes through it without any changes. However, according to quantum electrodynamics, the void is filled with virtual particles that continually appear and disappear. New research indicates that magnetic fields can alter a vacuum in such a way that it acts on the light passing through it, giving it polarity. VLT data showed that there is 16% linear light polarization in the case of RX J1856.
“Such a high degree of linear polarization, which we recorded, cannot be explained without the help of quantum electrodynamics concepts of birefringence in a vacuum,” Mignani summed up.
