Godzilla, a monster lurks in the Sunburst galaxy

We model the strong lensing effect in galaxy cluster PSZ1 G311.65-18.48 (z=0.443) with an improved version of hybrid method WSLAP+. extend number constraints by including position critical points, which are combined classic positional lensed galaxies. pay special attention to a transient candidate source (Tr) previously discovered giant Sunburst arc (z=2.37). Our lens predicts Tr be within fraction arcsecond from curve, having larger magnification factor than found, but still not large enough explain observed flux and lack counterimages. Possible counterimages discussed that would lower required Tr, extreme factors ($\mu>1000$) required, even case. The presence small mass perturber comparable dwarf ($M\sim 10^8 \,{\rm M}_{\odot}$) near is needed order morphology galaxy. discuss how existence this could potentially used constrain models dark matter. apparent brightness unresolved nature magnified object implies combination very luminous compact ($r<0.3$ pc). candidates discussed, hyperluminous star or accretion disc around intermediate-mass black hole (IMBH). Based on spectral information, we argue blue variable (LBV) caught during outburst most likely candidate. Owing luminosity dub it Godzilla.