{
  "eventId": "LIGO/Virgo/KAGRA S230518h",
  "circularId": 33851,
  "subject": "LIGO/Virgo/KAGRA S230518h: Swift/UVOT Upper Limits for MeerLICHT candidates: AT2023ixg and AT2023iyb",
  "bibcode": "2023GCN.33851....1B",
  "body": "A. A. Breeveld (UCL-MSSL), N. P. M. Kuin (UCL-MSSL), S. R. Oates (U. of Birmingham),  P. Brown (TAMU), M. De Pasquale (U. Messina), C. Gronwall (PSU), N. Klingler (NASA-GSFC/UMBC/CRESST II), 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) and E. Troja (U Tor Vergata, INAF) report on behalf of the Swift team:\n\nWe report Swift/UVOT observations of the candidates AT2023ixg and AT2023iyb (Johnston et al., Astronote 2023-121) found by the the MeerLICHT 0.65m wide-field telescope during the search for the EM counterpart of the LVC event S230518h (LIGO/VIRGO/KAGRA Collaboration GCN Circ. 33813).\n\nSwift/UVOT observations of these MeerLICHT candidates began 73 hours after the LVK trigger (LIGO/VIRGO/KAGRA Collaboration, GCN Circ. 33813) in the UV filters. We do not detect either of the 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:\n\nTarget    Filter   T_start(s) T_stop(s)  Exp(s)   3sigUL\n\nAT2023ixg   w1      267962     273767     164      18.4\n            m2      267775     278324     1067     19.6\n            w2      267587     278065     570      20.4\n\nAT2023iyb   m2      265880     272062     507      19.9\n            w2      265181     271869     1214     20.7\n\nThis circular is an official product of the Swift team.\n",
  "submitter": "Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>",
  "createdOn": 1684770774300
}