{
  "bibcode": "2021GCN.29787....1K",
  "body": "Paul Kuin (MSSL/UCL) and A. Melandri(INAF-OAB) report on behalf\nof the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 210410A\n(trigger 01042113; previously reported by Fermi/GBM in GCN #29777)\n1113 s after the Fermi trigger at 2021-04-10 00:53:16 UT.\nNo optical afterglow consistent with the XRT position (Melandri et\nal. GCN Circ. 29778) is detected in the initial UVOT exposures.\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 3-sigma UL\n\nv                 1129         1149           19         >17.0\nb                 5021         5109           85         >19.7\nu                 4817         5014          197         >19.9\nw1                4610         4809          197         >19.3\nm2                4403         4602          197         >19.4\nw2                1113         1125           12         >17.0\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.05 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 29787,
  "createdOn": 1618089369000,
  "email": "npkuin@gmail.com",
  "subject": "GRB 210410A: Swift/UVOT Upper Limits",
  "submitter": "Paul Kuin at MSSL  <npkuin@gmail.com>",
  "eventId": "GRB 210410A"
}