Astronomy: A star with an apparently solid surface has been discovered

An international research team has apparently discovered a star with a solid surface and no atmosphere. This was reported by the group led by Roberto Taverna of the University of Padua in the journal Science. Using NASA’s IXPE satellite, they found the unusual signature of the X-ray light of the star 4U 0142 + 61, which is 13,000 light-years from Earth. This is called a magnetar, which is a neutron star with a very strong magnetic field. In this case, the team explains, it is likely to be so strong that it makes the star’s outer layers a solid or at least a liquid. However, alternative explanations are still under investigation.

Polarization enables deep insights

The X-ray Imaging Explorer (IXPE) was launched a year ago and is operated by NASA and the Italian Space Agency ASI. The probe can measure X-ray polarization – the direction the waves oscillate – and that’s exactly what it did in 4U 0142 + 61. Team achieved, that a much smaller portion of the light is polarized than would be expected if it passed through the stellar atmosphere. In addition, the degree of polarization of the high-energy parts of the radiation is rotated exactly 90 degrees to that of the weaker energy radiation. Together, they will refer to the hard surface.

The team explains that they believe the star’s solid crust is made up of an ionic lattice held together by an enormous magnetic field. According to this, the atoms will not be spherical either, but are elongated in the direction of the field. Generally will Prove the discovery presented in scienceIt is possible to obtain inaccessible information about the structure of these celestial bodies through polarization analysis. The team now wants to study neutron stars with a similar magnetic field to discover how the high temperatures in these celestial bodies interact with the magnetic field to alter the surface. IXPE is scheduled to operate for at least another year.

(mo)