{
  "bibcode": "2020GCN.27648....1K",
  "body": "N. P. M. Kuin (UCL-MSSL) reports on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the INTEGRAL GRB 200424A\n(Mereghetti et al. GCN Circ. 27634) between T0+17 ks and T0+31 ks,\nwhere T0 = 2020-04-24 12:06:45 UT.\nWe report here the UOT results for source #1 found by the Swift/XRT\n(D'Avanzo et al., GCN Circ. 27640).\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(ks)   T_stop(ks)      Exp(s)         Mag\n\nv                   18           30          236         >19.1\nb                   17           30          236         >20.2\nu                   17           30          236         >19.9\nw1                  17           30          492         >19.9\nm2                  17           31         2678         >20.8\nw2                  17           30          944         >20.4\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": 27648,
  "createdOn": 1587856823000,
  "email": "npkuin@gmail.com",
  "subject": "GRB 200424A: Swift/UVOT Upper Limits",
  "submitter": "Paul Kuin at MSSL  <npkuin@gmail.com>",
  "eventId": "GRB 200424A"
}