{
  "bibcode": "2021GCN.30742....1H",
  "body": "Y.-D. Hu, T.-R. Sun, E. Fernandez-Garcia, A. J. Castro-Tirado and M.D. Caballero-Garcia (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar and I. Carrasco (UMA), I. H. Park (SKKU) on behalf of a larger collaboration, report:\r\n\r\nWe triggered the 60cm BOOTES-5/JGT robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) for the Fermi trigger of GRB 210827A (Fermi GBM team, GCNC 30724) in order to monitor the Swift/BAT-GUANO error region (DeLaunay et al. GCNC 30732) on 28 Aug 05:25 UT (~ 0.81 day after trigger). In the co-added clear image (8 x 60 s), no optical afterglow is detected within the BAT error region or at the source 3 position later reported by the Swift-XRT (Evans et al., GCNC 30733; Gropp et al., GCNC 30734) down to 19.7 mag. This non-detection is consistent with the report by MASTER-Net (Lipunov et al., GCNC 30736).\r\n\r\nWe thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for its excellent support.",
  "circularId": 30742,
  "createdOn": 1630253192000,
  "email": "huyoudong072@hotmail.com",
  "subject": "GRB 210827A: BOOTES-5/JGT optical upper limit",
  "submitter": "Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>",
  "eventId": "GRB 210827A"
}