Dimmer Distant Supernova

Dimmer Distant Supernova
These Hubble Space Telescope images show the galaxy in which the Type Ia supernova SN 1997ff occurred.
This supernova, more than 10 billion ly  away, was dimmer than expected, indicating that the distance to it is
greater than the distance it would have if the universe had been continually slowing  down since the Big Bang.
This supports the notion that an outward (cosmological) force is acting over vast distances in the universe. The
arrow on the left inset shows the galaxy in which the supernova was discovered. The bright spot on the right
inset shows the supernova by subtracting the constant light emitted by all the other nearby objects. (Adam
Riess, Space Telescope