THE FIRST STARS AND THE ORIGIN OF CHEMICAL ELEMENTS

Massimo Stiavelli , Space Telescope Science Institute and Johns Hopkins University , in conversation with Giovanni Rosotti , Professor of Astrophysics, University of Milan.

Immediately after its formation, the Universe consisted primarily of hydrogen and helium, with heavier elements almost entirely absent. This poses a double problem: the formation of stars and the origin of other elements. The stars we see forming in our galaxy require heavier elements to form dust and allow the gas to cool before they can form. The first stars must have formed in the absence of heavier elements and are thought to have had much greater masses than the stars we see in our galaxy today. These stars would then have begun to produce the first heavier elements. In this presentation, I will describe the formation of the first stars and how observations with the James Webb Space Telescope can help us test these ideas.