AlbaNova Colloquium

JWST: One Giant Leap Towards Observing the First Stars

by Prof. Dan Coe

With the Hubble Space Telescope, we have looked back in time and witnessed a rich diversity of galaxies growing, merging, and taking shape over 13 billion years of cosmic history. But the most distant galaxies in the early universe are too small and faint to study in detail with Hubble, leaving us with many questions. When did the first stars and galaxies form? Did any early galaxies look like our Milky Way? And what were they made of? The James Webb Space Telescope (JWST) is beginning to answer these questions and pose new ones. In only its second year of operation, JWST has already taken a giant leap towards discovering the first stars. I will discuss observations using gravitational lensing that reveal individual stars including Earendel observed 13 billion years ago. We also observe star clusters dating back to even earlier times in the Cosmic Gems Arc. I will show spectroscopy that reveals heavy elements created by stars less than 400 million years after the Big Bang. And this is just the beginning for JWST. We hope it may continue observing for 20 years or more.