Detection of an outburst one year prior to the explosion of SN 2011ht
  Using imaging from the Pan-STARRS1 survey, we identify a precursor outburst
at epochs 287 and 170 days prior to the reported explosion of the purported
Type IIn supernova (SN) 2011ht. In the Pan-STARRS data, a source coincident
with SN 2011ht is detected exclusively in the \zps\ and \yps-bands. An absolute
magnitude of M$_z\simeq$-11.8 suggests that this was an outburst of the
progenitor star. Unfiltered, archival Catalina Real Time Transient survey
images also reveal a coincident source from at least 258 to 138 days before the
main event. We suggest that the outburst is likely to be an intrinsically red
eruption, although we cannot conclusively exclude a series of erratic outbursts
which were observed only in the redder bands by chance. This is only the fourth
detection of an outburst prior to a claimed SN, and lends credence to the
possibility that many more interacting transients have pre-explosion outbursts,
which have been missed by current surveys.
