{
  "bibcode": "2015GCN.18322....1B",
  "body": "A. A. Breeveld (UCL-MSSL) and V. D'Elia (ASDC) report on behalf of the\nSwift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 150915A\n295s after the BAT trigger (D'Elia et al., GCN Circ. 18315).\nNo optical afterglow consistent with the XRT position (D���Elia et al.,\nGGN Circ. 18315) or the GROND position (Yates et al., GCN Circ. 18317)\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 finding\nchart (FC) exposure and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nu_FC               295          545          246         >20.0\nwhite              576          769           39         >19.9\nv                  625          818           39         >18.2\nb                  550          745           39         >19.2\nu                  295         4267          434         >20.0\n\nThe magnitudes in the table are not corrected for the Galactic\nextinction due to the reddening of E(B-V) = 0.10 in the direction of the\nburst (Schlegel et al. 1998).",
  "circularId": 18322,
  "createdOn": 1442426019000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 150915A: Swift UVOT upper limits",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 150915A"
}