{
  "bibcode": "2020GCN.28565....1M",
  "body": "F. E. Marshall (NASA/GSFC) and J. D. Gropp (PSU)\r\n\r\nreport on behalf of the Swift/UVOT team:\r\n\r\n\r\n\r\nThe Swift/UVOT began settled observations of the field of GRB 201006A\r\n\r\n88 s after the BAT trigger (Gropp et al., GCN Circ. 28560).\r\n\r\nNo optical afterglow consistent with the XRT position\r\n\r\n(Goad et al. GCN Circ. 28562)\r\n\r\nis detected in the initial UVOT exposures.\r\n\r\nPreliminary 3-sigma upper limits using the UVOT photometric system\r\n\r\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first\r\n\r\nfinding chart (FC) exposure and subsequent exposures are:\r\n\r\n\r\n\r\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\r\n\r\n\r\n\r\nwhite_FC            88          238          147         >21.1\r\n\r\nu_FC               300          549          246         >20.2\r\n\r\nwhite               88         1539          385         >21.0\r\n\r\nv                  629         1423           97         >18.9\r\n\r\nb                  555         1521           97         >19.8\r\n\r\nu                  300          722          265         >20.3\r\n\r\nw1                 678         1472           97         >18.7\r\n\r\nw2                1205         1225           19         >17.3\r\n\r\n\r\n\r\nThe magnitudes in the table are not corrected for the Galactic extinction\r\n\r\ndue to the reddening of E(B-V) = 1.27 in the direction of the burst\r\n\r\n(Schlegel et al. 1998).",
  "circularId": 28565,
  "createdOn": 1602018433000,
  "email": "marshall@milkyway.gsfc.nasa.gov",
  "subject": "GRB 201006A: Swift/UVOT Upper Limits",
  "submitter": "Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 201006A"
}