{
  "bibcode": "2017GCN.21727....1K",
  "body": "Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),\nBoer, M., Laugier, R. (CNRS-ARTEMIS),\nGendre B. (UVI - Etelman Obs.) report:\n\nWe imaged the field of GRB 170823A detected by SWIFT\n(trigger 769177) with the TAROT robotic telescope (D=25cm)\nlocated at the Calern observatory, France.\n\nThe observations started 28s after the GRB trigger\n(18s after the notice). The elevation of the field decreased from\n3 degrees above horizon and weather conditions\nwere very good.\n\nThe first image is trailed with a duration of 60.0s\n(see the description in Klotz et al., 2006, A&A 451, L39).\nWe do not detect any OT with a limiting magnitude of:\nt0+28s to t0+88s : Rlim = 15.1\n\nThe second image is 30.0s exposure in tracking mode:\nt0+101s to t0+131s : Rlim = 15.1\n\nWe co-added a series of exposures:\nt0+101s to t0+395s : Rlim = 16.8\n\nMagnitudes were estimated with the nearby USNO-B1 stars\nand are not corrected for galactic dust extinction.",
  "circularId": 21727,
  "createdOn": 1503871291000,
  "email": "Alain.Klotz@free.fr",
  "subject": "GRB 170823A: TAROT Calern observatory optical observations",
  "submitter": "Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>",
  "eventId": "GRB 170823A"
}