{
  "bibcode": "2016GCN.19256....1K",
  "body": "Paul Kuin (MSSL/UCL) and L.M. McCauley (PSU) report on behalf of the\nSwift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 160401A\n43ks s after the INTEGRAL trigger (Mereghetti et al., GCN Circ.19251).\nNo optical afterglow consistent with the INTEGRAL position is detected\nin the initial UVOT exposures. The burst location was also observed by\nMASTER-IAC (Rebolo et al., GCN Circ. no. 19252); LT (Guidorzi et al.\nGCN Circ. no. 19254), and the Zadko observatory (Klotz et al. GCN\nCirc. 19255); none of whom observed an afterglow.\nPreliminary 3-sigma upper limits using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures\nare:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite            43678        44209          522         >20.8\nv                44509        45370          843         >19.5\nu                42847        43671          811         >19.9\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 1.13 in the direction of the burst\n(Schlegel et al. 1998).\n\n[GCN OPS NOTE(02apr16):  The letter 'A' was added to the GRB name.]",
  "circularId": 19256,
  "createdOn": 1459627699000,
  "email": "npkuin@gmail.com",
  "subject": "GRB 160401A: Swift/UVOT Upper Limits",
  "submitter": "Paul Kuin at MSSL  <npkuin@gmail.com>",
  "eventId": "GRB 160401A"
}