{
  "bibcode": "2015GCN.18255....1D",
  "body": "M. De Pasquale (UCL-MSSL) and D. Malesani (DARK/NBI) report on behalf of\nthe Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 150907A\n8821 s after the MAXI trigger (Suzuki et al., GCN Circ. 18246).\n\nNo optical source consistent with the XRT Source 1 position given in\nKennea et al. (GCN Circ. 18250) is detected in the summed u band exposures.\n\nWe note however, that there is source in the DSS catalogue consistent\nwith the XRT Source 1 position.\n\n\nPreliminary 3-sigma upper limits using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the exposure\nfor source 1 is:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nu                8821        18835         336           >19.5\n\n\nThe magnitudes in the table are not corrected for the Galactic \nextinction due\nto the reddening of E(B-V) = 0.08 in the direction of the burst \n(Schlegel et al. 1998).\n\n-- \n\nDr. Massimiliano De Pasquale\nResearch associate - Swift UVOT scientist\nMullard Space Science Laboratory, University College London",
  "circularId": 18255,
  "createdOn": 1441713456000,
  "email": "m.depasquale@ucl.ac.uk",
  "subject": "GRB150907A: Swift/UVOT observations",
  "submitter": "Massimiliano de Pasquale at IASF-Palermo  <m.depasquale@ucl.ac.uk>",
  "eventId": "GRB 150907A"
}