The Governors of the University of Alberta

Published purpose

In March 2023, a neutron star (a dense stellar corpse) brightened by a factor of 10,000 in the X-rays, as it consumed material torn from a small companion star. This neutron star is located in the globular cluster Terzan 5, a cluster of about a million old stars that is rich in neutron stars. AstroSat observed the X-rays from this neutron star with its three X-ray instruments. We will study the AstroSat data, along with data from other X-ray instruments, to search for pulsations at the neutron star spin period; to look for evidence of gas blocking our view of the neutron star; and to study light reflected from the material falling onto the neutron star. We hope to infer the spin of the neutron star, the orbital period of the neutron star and its companion star, and how the infalling material falls onto the neutron star. This study can help us understand the physics of neutron stars, and of how they suck mass from companion stars and consume it.