Free Astronomy Magazine November-December 2022

NOVEMBER-DECEMBER 2022 Pair-instability supernova explosions happen when photons in the center of a star spontaneously turn into electrons and positrons — the posi- tively charged antimatter counter- part to the electron. This conversion reduces the radiation pressure inside the star, allowing gravity to over- come it and leading to the collapse and subsequent explosion. Unlike other supernovae, these dra- matic events leave no stellar rem- nants, such as a neutron star or a black hole, and instead eject all their material into their surroundings. There are only two ways to find evi- dence of them. The first is to catch a pair-instability supernova as it hap- pens, which is a highly unlikely hap- penstance. The other way is to iden- tify their chemical signature from the material they eject into interstel- lar space. For their research, the astronomers studied results from a prior observa- tion taken by the 8.1-meter Gemini North telescope using the Gemini Near-Infrared Spectrograph (GNIRS). A spectrograph splits the light emit- ted by celestial objects into its con- stituent wavelengths, which carry information about which elements the objects contain. Gemini is one of the few telescopes of its size with suitable equipment to perform such observations. T his artist’s impression shows a field of Population III stars as they would have appeared a mere 100 million years after the Big Bang. Astronomers may have discovered the first signs of their ancient chemical remains in the clouds surrounding one of the most distant quasars ever detected. [NOIRLab/NSF/AURA/J. da Silva/Spaceengine]