Free Astronomy Magazine March-April 2023

25 MARCH-APRIL 2023 ASTRO PUBLISHING ternal processes of the star have not altered the composition of the at- mosphere which therefore remains absolutely original. It is like having an intact sample of the environment in which this star formed, about thir- teen billion years ago.” “This discovery is also extremely im- portant from a theoretical point of view: it clarifies the characteristics of the first supernovae that pol- luted the environment out of which this star formed, ruling out several theoretical models and putting an end to a long debate.” , says Jonay González Hernández, astronomer of the IAC, Tenerife, and co-author of this work. The team is multidisciplinary and is made up of researchers from Spain, Italy, France, Portugal and Switzer- land who built the ESPRESSO spec- trograph, which is proving to be one of the best and most modern tools for studying the formation of the first stars. ESPRESSO (Echelle SPec- trograph for Rocky Exoplanets and Stable Spectroscopic Observations) is a VLT ultra-stable high-resolution spectrograph developed by research institutions in Switzerland, Italy, Spain and Portugal, and ESO (Euro- pean Southern Observatory), in- stalled and in operations at the VLT telescope in Paranal Observatory (ESO, Chile) since October 2018. A rtist’s impression of the bi- nary star SMSS1605-1443. [Gabriel Pérez Díaz (IAC)] !