How did the various types of galaxies form?
Galaxies come in a variety of shapes and sizes, believed to reflect the differing ways they form. To understand the evolution of a galaxy, astronomers need to be able to study the individual stars it is formed from, comparing their ages and composition. Our own Milky Way galaxy and its nearest neighbours represent only a small fraction of the diverse range of galaxy types seen throughout the Universe- to understand further away or denser galaxies, such as giant elliptical galaxies, astronomers will require an ELT. When did stars first start to shine? At the moment astronomers cannot look far enough back in time to see the first stars. Since light takes time to travel through space towards Earth, the further away astronomers look, the further back in time the light was emitted. While the first stars will not be visible even to an ELT, the most extreme supernovae of these stars may just be. Since all massive stars explode as supernovae, counting supernovae counts massive stars, from whic
