© NASA, ESA, A. Riess (STScI).
The Hubble Space Telescope, able to collect images free from the limitations imposed by looking through the Earth's atmosphere, has been a critical tool in the discovery of the highest redshift SNae Ia ever observed. The top row of images shows several of these supernovae near maximum light, while the bottom row of images shows the host galaxies without the supernovae. This sample of supernovae falls on the right-hand side of the Hubble diagram, the region of the plot in which the evidence for dark energy is most obvious. Adding these, together with 16 other HST-detected SNae Ia, to the existing Hubble diagram in 2007 cut in half the uncertainty in our knowledge of the Hubble parameter, and strengthened the case for dark energy. (Unit: 11)