{
  "bibcode": "2021GCN.30593....1W",
  "body": "Alan M. Watson (UNAM), Nat Butler (ASU), Eleonora Troja (GSFC/UMD), Rosa L.\nBecerra (UNAM), Simone Dichiara (GSFC/UMD), Alexander Kutyrev (GSFC/UMD),\nWilliam H. Lee (UNAM), Diego Gonzalez (UNAM), Oc��lotl Lopez (UNAM), Margarita\nPereyra (UNAM), and Srihari Ravi (ASU) report:\n\nWe observed the field of the Fermi GBM/LAT event GRB 210802A (Longo et al., GCN\nCirc., 30589; Roberts et al., GCN Circ., 30590) with the DDOTI wide-field imager\nat the Observatorio Astron��mico Nacional on Sierra San Pedro Martir (\nhttp://ddoti.astroscu.unam.mx) from 2021-08-03 03:35 to 07:37 UTC (7.45 to 11.48\nhours after the trigger).\n\nWe observed a region of about 14 degrees in RA by 10 degrees in declination,\nwith a 1 x 2 grid of pointings centered on the Fermi GBM Final Position\n15:19:40.80 +30:18:00.0 (J2000) and including the entire LAT uncertainty region\n(Longo et al., GCN Circ., 30589). We obtained about 105 minutes exposure on the\nLAT uncertainty region. We obtained AB photometry by calibration against the\nAPASS catalog.\n\nComparing to the Pan-STARRS DR1 catalog, we detect no uncatalogued point sources\nin the LAT uncertainty region to a 10-sigma limiting magnitude of w = 21.0.\n\nAt the position of the candidate X-ray afterglow (Sbarufatti et al., GCN Circ.,\n30591), we detect no point source to a 5-sigma limiting magnitude of w = 21.8.\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro M��rtir.",
  "circularId": 30593,
  "createdOn": 1628036084000,
  "email": "alan@astro.unam.mx",
  "subject": "GRB 210802A: DDOTI Upper Limits",
  "submitter": "Alan M Watson at UNAM  <alan@astro.unam.mx>",
  "eventId": "GRB 210802A"
}