GCN Circular 33832

LIGO/Virgo/KAGRA S230518h: Swift/UVOT Upper Limits for Swope candidates: SSS23a, SSS23b and SSS23c S. R. Oates (U. of Birmingham), A. A. Breeveld (MSSL-UCL), P. Brown (TAMU), M. De Pasquale (U. Messina), C. Gronwall (PSU), N. Klingler (NASA-GSFC/UMBC/CRESST II), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), M. J. Page (UCL-MSSL), M. H. Siegel (PSU), A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), A. D’Aì (INAF-IASFPA), P. D’Avanzo (INAF-OAB), V. D’Elia (ASI-SSDC & INAF-OAR), S. Dichiara (PSU), P.A. Evans (U. Leicester), R.A.J. Eyles-Ferris (U. Leicester), D. Hartmann (Clemson University), J.A. Kennea (PSU), S. Laha (NASA/GSFC), A.Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), P. O’Brien (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), D. M. Palmer (LANL), S. Ronchini (PSU), T. Sbarrato (INAF-OAB), B. Sbarufatti (INAF-OAB), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (U. Toronto), E. Troja (U Tor Vergata, INAF) report on behalf of the Swift team: We report Swift/UVOT observations of the candidates SSS23a, SSS23b and SSS23c (Coulter et al., GCN Circ. 33829) found by the Swope 1-m telescope during the search for the EM counterpart of the LVC event S230518h (LIGO/VIRGO/KAGRA Collaboration GCN Circ. 33813). Swift/UVOT observations of the Swope candidates began 1.5 days after the LVK trigger (LIGO/VIRGO/KAGRA Collaboration GCN Circ. 33813). We do not detect any of the 3 Swope candidates in the UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the exposures are: Target Filter T_start(s) T_stop(s) Exp(s) 3sigUL SSS23a u 129503 135881 288 >19.2 SSS23a w1 129079 135788 585 >19.9 SSS23a m2 128445 135607 879 >20.2 SSS23a w2 129713 136188 753 >20.1 SSS23b u 140770 140997 223 >19.1 SSS23b w1 140310 140765 448 >19.8 SSS23b m2 139622 140304 671 >20.1 SSS23b w2 141004 141319 309 >19.6 SSS23c u 130526 141885 131 >18.7 SSS23c w1 130415 141799 264 >19.3 SSS23c m2 130250 141633 395 >19.6 SSS23c w2 130586 142008 133 >19.0 This circular is an official product of the Swift team.