Free Astronomy Magazine March-April 2024

18 MARCH-APRIL 2024 ASTRO PUBLISHING by ESO − Bárbara Ferreira W hen massive stars reach the end of their lives, they collapse under their own gravity so rapidly that a violent ex- plosion known as a supernova en- sues. Astronomers believe that, after all the excitement of the ex- plosion, what is left is the ultra- dense core, or compact remnant, of the star. Depending on how massive the star is, the compact remnant will be either a neutron star — an object so dense that a teaspoon of its ma- terial would weigh around a trillion kilograms here on Earth — or a black hole — an object from which nothing, not even light, can escape. Astronomers have found many clues hinting at this chain of events in the past, such as finding a neutron star within the Crab Nebula, the gas cloud left behind when a star ex- ploded nearly a thousand years ago. A direct link between supernovae, neutron stars and black holes