Gamma-ray eclipses shed new light on spider pulsars – January 26, 2023

A gamma-ray pulsar is a compact neutron star that accelerates charged particles to relativistic speeds in its extremely strong magnetic field. This process produces gamma radiation (violet) far above the surface of the compact remains of the star, for example, while radio waves (green) are emitted over the magnetic poles in the form of a cone. The rotation moves the emission regions across the terrestrial line of sight, making the pulsar light up periodically in the sky. © NASA/Fermi/Cruz de Wilde
Seven rare eclipsing binaries identified and five neutron stars weighed
Mankind has watched the cosmic ballet of eclipses for millennia. Solar and lunar eclipses, those of Jupiter’s moons, and stellar occultations by planets and asteroids have also provided new physical measurements and insights about our Universe. Using NASA’s Fermi Gamma-ray Space Telescope, astronomers have now identified seven rare stellar binary systems in which a neutron star is eclipsed by its stellar companion. This allowed the international research team led by scientists from the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Hannover to weigh those neutron stars. Their results were published in Nature Astronomy today. Precisely measuring neutron star masses improves our understanding of matter in extreme conditions and has implications for fundamental physics. In the future, these seven binary systems could also provide new opportunities to observe Einstein’s theory of general relativity in action.