Harvey Richer Department of Physics and Astronomy University of British Columbia

Friday, May 3, 2013 at AMNH Title: White Dwarfs - all you need to know about the Universe

Abstract: What are some of the big questions in astronomy these days? 1) What is the age of the Universe? 2) When did the galaxies form? 3) How did they form? 4) When did most of the stars form? 5) What can we learn about fundamental physics from astronomical observations? 6) Is there an efficient way to find evidence for planets in the environment in which they formed?

In this talk I will show how our total of 414 HST orbits over the past 15 years has provided insight into most of these questions. In particular, I'll mention how we derived an age for the oldest stars thus confronting cosmologically derived ages for the Universe, how we have recognized an age difference between the halo and thick disk of the Galaxy, how we have tested basic white dwarf cooling theory and found it to be wanting, and how we have been searching for evidence of planets in very old stellar clusters, which, if found could suggest an early rise to life in the Universe.