"The 2004 prize in Observational or Theoretical Astronomy and Astrophysics was awarded to Andrea M. Ghez of UCLA "for her pioneering high-resolution infrared observations that provide evidence for, and establish the mass of, the supermassive blackhole in the center of the galaxy" and Adam G. Riess of the Space Telescope Science Institute in Baltimore, Maryland "for his contributions to the observational study of distant Type Ia supernovae that reveal the accelerating expansion of the universe and the possible existence of dark energy.