McBrien, O. R.O. R.McBrienSmartt, S. J.S. J.SmarttHuber, M. E.M. E.HuberRest, A.A.RestChambers, K. C.K. C.ChambersBarbieri, C.C.BarbieriBulla, M.M.BullaJha, S.S.JhaGromadzki, M.M.GromadzkiSrivastav, S.S.SrivastavSmith, K. W.K. W.SmithYoung, D. R.D. R.YoungMcLaughlin, S.S.McLaughlinInserra, C.C.InserraNicholl, M.M.NichollFraser, M.M.FraserMaguire, K.K.MaguireChen, T-WT-WChenWevers, T.T.WeversAnderson, J. P.J. P.AndersonMuller-Bravo, T. E.T. E.Muller-BravoOlivares, F. E.F. E.OlivaresKankare, E.E.KankareGal-Yam, A.A.Gal-YamWaters, C.C.Waters2025-12-302025-12-3020211365-2966https://hdl.handle.net/20.500.12740/24143Time domain astronomy was revolutionized 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 optimizing search strategies to maximize 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 similar or equal to 200 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 an AT2018kzr-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.Acceso Abiertosurveyssupernovae: generalblack holeneutron star mergershttp://dx.doi.org/10.1093/mnras/staa3361