The First Stars in the Universe
Professor Bengt Gustafsson
Uppsala University
12 May 2006, Friday 13:30
Lecture room (Sal) F, Theoretical Physics, Sölvegatan 14A
Abstract:
Since all heavy chemical elements are supposed to be made in stars one
would expect that low-mass (slowly evolving) stars from the first stellar
generation, with no heavy elements at all in their surface layers, should
be possible to find. Such a generation could have had very great
significance for the formation and early evolution of galaxies. For 35
years searches for remaining such stars have been conducted, with negative
results. In the last five years, however, indirect evidence for a very
early stellar generation, preceding the formation of galaxies, has been
traced in the Cosmic Microwave Background. Theoretically, such stars may
be expected to evolve in ways remarkably different from those of normal
stars. A few stars with very low abundances of heavy elements, and quite
odd elemental composition, have also been found. What do they tell us
about the first stellar generation?