{
  "bibcode": "2023GCN.33739....1K",
  "eventId": "GRB 230506C",
  "body": "Paul Kuin (MSSL/UCL) and A Tohuvavohu (U Toronto) report on behalf\nof the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 230506C\n4.6 ks after the BAT trigger (Tohuvavohu et al., GCN Circ. 33731).\nNo optical afterglow consistent with the enhanced XRT position is\ndetected in the initial UVOT exposures.\n\nPreliminary 3-sigma upper limits using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first\nfinding chart (FC) exposure and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite             4625         4825          197         >18.5\nv                 5036         5236          197         >19.2\nu                 5614         5814          197         >19.6\nuvw1              5446         5646          197         >20.6\nuvm2              5241         5441          197         >21.5\nuvw2              4831         5031          197         >20.3\n",
  "circularId": 33739,
  "createdOn": 1683458847438,
  "submitter": "Paul Kuin at MSSL <npkuin@gmail.com>",
  "subject": "GRB 230506C: Swift/UVOT Upper Limits"
}