  Time domain astronomy was revolutionised with the discovery of the first
kilonova, AT2017gfo, in August 2017 which was associated with the gravitational
wave signal GW170817. Since this event, numerous wide-field surveys have been
optimising search strategies to maximise their efficiency of detecting these
fast and faint transients. With the Panoramic Survey Telescope and Rapid
Response System (Pan-STARRS), we have been conducting a volume limited survey
for intrinsically faint and fast fading events to a distance of $D\simeq200$
Mpc. Two promising candidates have been identified from this archival search,
with sparse data - PS15cey and PS17cke. Here we present more detailed analysis
and discussion of their nature. We observe that PS15cey was a luminous, fast
declining transient at 320 Mpc. Models of BH-NS mergers with a very stiff
equation of state could possibly reproduce the luminosity and decline but the
physical parameters are extreme. A more likely scenario is that this was a
SN2018kzr-like merger event. PS17cke was a faint and fast declining event at 15
Mpc. We explore several explosion scenarios of this transient including models
of it as a NS-NS and BH-NS merger, the outburst of a massive luminous star, and
compare it against other known fast fading transients. Although there is
uncertainty in the explosion scenario due to difficulty in measuring the
explosion epoch, we find PS17cke to be a plausible kilonova candidate from the
model comparisons.

High Energy Astrophysical Phenomena