The Disappearance of the Red Supergiant Progenitor of Supernova 2008bk
  Massive stars end their lives in spectacular supernova explosions.
Identifying the progenitor star is a test of stellar evolution and explosion
models. Here we show that the progenitor star of the supernova SN 2008bk has
now disappeared, which provides conclusive evidence that this was the death of
a red supergiant star.
