The Decline and Fall of the Youngest Planetary Nebula
  The Stingray Nebula, aka Hen3-1357, appeared for the first time in 1990 when
bright nebular lines and radio emission that had not been observed before were
unexpectedly discovered (Parthasarathy et al. 1993). In the ensuing years the
nebula faded precipitously. We report changes in shape and large decreases in
its nebular emission-line fluxes based on well-calibrated images obtained by
the Hubble Space Telescope in 1996 and 2016. Hen3-1357 is now a "recombination
nebula".
