“We’re made of star stuff,” astronomer Carl Sagan famously said. Nuclear reactions that happened in ancient stars generated much of the material that makes up our bodies, our planet and our solar system. When stars explode in violent deaths called supernovae, those newly formed elements escape and spread out in the universe.
About 4.6 billion years ago, a cloud of gas and dust that eventually formed our solar system was disturbed. The ensuing gravitational collapse formed the proto-Sun with a surrounding disc where the planets were born. Now, forensic evidence from meteorites provides conclusive evidence that a low-mass supernova was the trigger.
The eerie glow of a dead star, which exploded long ago as a supernova, reveals itself in this NASA Hubble Space Telescope image of the Crab Nebula in the constellation of Taurus. But don’t be fooled. The ghoulish-looking object still has a pulse. Buried at its centre is the star’s telltale heart — a neutron star which beats with rhythmic precision.
Pulsars are rapidly spinning neutron stars that emit electromagnetic radiation in a sweeping, lighthouse-like beam. They are dramatic, powerful probes of supernovae, their progenitor stars. Astronomers have measured the orbital parameters of four millisecond pulsars in the globular cluster 47 Tucanae and modelled their possible formation and evolution paths.
Using data from NASA’s Fermi Gamma-ray Space Telescope and other facilities, an international team has found the first gamma-ray binary in another galaxy and the most luminous one ever seen. The dual-star system, dubbed LMC P3, contains a massive star and a crushed stellar core that interact to produce a cyclic flood of gamma rays.
It is only as recently as 2013 that astrophysicists found individual black holes in globular clusters via rare phenomena in which a companion star donates material to the black hole. New research by the University of Surrey on a globular cluster known as NGC 6101 shows that it could host several hundred black holes — a phenomenon that until recently was thought impossible.
Astronomers have made the first accurate measurement of the abundance of oxygen in a distant galaxy. Oxygen is created inside stars and released into interstellar gas when stars die. Quantifying the amount of oxygen, the third-most abundant chemical element in the universe, is key to understanding how matter cycles in and out of galaxies.
This new NASA/ESA Hubble Space Telescope image reveals the beating heart of one of the most visually appealing, and most studied, supernova remnants known — the Crab Nebula in the constellation Taurus. At the centre of this nebula the spinning core of a deceased star breathes life into the gas that surrounds it.