{
  "bibcode": "2021GCN.30529....1L",
  "body": "GRB 210724A: Swift/UVOT Upper Limits\n\nS. J. LaPorte (PSU) and P. D'Avanzo (INAF-OAB)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 210724A\n125 s after the BAT trigger (D'Avanzo et al., GCN Circ. 30497).\nNo optical afterglow consistent with the XRT position\n(D'Avanzo et al. GCN Circ. 30497)\nis 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\n\nwhite_FC           125          275          147         >20.8\nu_FC               283          513          226         >20.1\nwhite              125          275          147         >20.8\nu                  283          513          227         >20.1\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.097 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 30529,
  "createdOn": 1627366633000,
  "email": "sjl5346@psu.edu",
  "subject": "GRB 210724A: Swift/UVOT Upper Limits",
  "submitter": "Sam LaPorte at PSU  <sjl5346@psu.edu>",
  "eventId": "GRB 210724A"
}