Late-Time Dust Emission from the Type IIn Supernova 1995N
  The Type IIn supernovae (SNe IIn) have been found to be associated with
significant amounts of dust. These core-collapse events are generally expected
to be the final stage in the evolution of highly-massive stars, either while in
an extreme red supergiant phase or during a luminous blue variable phase. Both
evolutionary scenarios involve substantial pre-supernova mass loss. I have
analyzed the SN IIn 1995N in MCG -02-38-017 (Arp 261), for which mid-infrared
archival data obtained with the Spitzer Space Telescope in 2009 (~14.7 yr after
explosion) and with the Wide-field Infrared Survey Explorer (WISE) in 2010
(~15.6--16.0 yr after explosion) reveal a luminous (~2e7 L_sun) source detected
from 3.4 to 24 micron. These observations probe the circumstellar material, set
up by pre-SN mass loss, around the progenitor star and indicate the presence of
~0.05--0.12 M_sun of pre-existing, cool dust at ~240 K. This is at least a
factor ~10 lower than the dust mass required to be produced from SNe at high
redshift, but the case of SN 1995N lends further evidence that highly massive
stars could themselves be important sources of dust.
