Abstract

Finding and understanding the nature of the first stars at cosmic dawn is one of the most important and most ambitious goals for modern astrophysics. The first populations of stars produced the first chemical elements heavier than helium and formed the first, small protogalaxies, which then evolved, across the cosmic epoch, into the large and mature galaxies, such as the Milky Way and those in our local neighbour. Equally important and equally challenging is the search, in the early Universe, of the seeds of the first population of black holes, which later evolved in the supermassive black holes at the centre of galaxies, with masses even exceeding a billion times the mass of the Sun. When matter accretes on such supermassive black holes it can become so luminous to vastly outshine the light emitted by all stars in their host galaxy.

Since its launch, about two years ago, the James Webb Space Telescope has been revolutionizing this area of research. Its sensitivity in detecting infrared light from the remotest parts of the Universe is orders of magnitude higher than any previous observatory, an historical leap in astronomy and, more broadly, in science. I will presents some of the first, extraordinary discoveries from the Webb telescope, which have resulted in several unexpected findings. I will also discuss the new puzzles and areas of investigation that have been opened by Webb’s observations, how these challenge theoretical models, and the prospects of further progress in the coming years.