{
  "circularId": 36179,
  "createdOn": 1713529967309,
  "submittedHow": "email",
  "bibcode": "2024GCN.36179....1L",
  "body": "S. J. LaPorte (PSU) and T. M. Parsotan (GSFC)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 240411B\n190 s after the BAT trigger (Parsotan et al., GCN Circ. 36063). A source\nconsistent\nwith the XRT position (Goad et al., GCN Circ. 36065) and the reported\noptical transient (Izzo et al. GCN 36064; Schneider et\nal. GCN 36067; Ror et al. GCN 36069; Ugarte Postigo et al. GCN 36074; Aryan\net al. GCN 36077; Pankov et al. GCN 36078) is detected in the initial UVOT\nexposures.\n\nPreliminary detections and 3-sigma upper limits using the UVOT photometric\nsystem\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures\nare:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\n\nb                      6480          6680           196        >19.84\nv                      7096          7295           196        >18.58\nuvw2                6891          7091           196        >19.45\nwhite                6685          6885           196        >20.54\nwhite                 198            348           147           20.08+-0.27\n\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.022 in the direction of the burst\n(Schlegel et al. 1998).\n",
  "eventId": "GRB 240411B",
  "subject": "GRB 240411B: Swift/UVOT Detection",
  "submitter": "Sam LaPorte at PSU <sjl5346@psu.edu>"
}