{
  "bibcode": "2019GCN.24287....1W",
  "body": "Alan M. Watson (UNAM), Eleonora Troja (GSFC), Nat Butler (ASU), Rosa L.\nBecerra (UNAM), Diego Gonz��lez (UNAM), William H. Lee (UNAM), Margarita\nPereyra (UNAM), Carlos Rom��n-Z����iga (UNAM) and Alexander Kutyrev (GSFC)\nreport:\n\nWe observed the field of GRB 190427A (Tohuvavohu et al., GCN Circ.\n24261) with the COATLI 50-cm telescope and interim imager at the\nObservatorio Astron��mico Nacional on the Sierra de San Pedro M��rtir\n(http://coatli.astroscu.unam.mx) from 2019-02-04 05:28:30 to 06:36:27\n(from 0.9 to 2.0 hours after the trigger), obtaining a total of 3000\nseconds of exposure in the w filter.\n\nComparing to the USNO and Pan-STARRS1 catalogs, we do not detect any new\nsources brighter than w = 21 in the BAT error region.\n\nOur w magnitudes are calibrated against the Pan-STARRS1 catalog, are on \nan approximate AB system, and are not corrected for Galactic extinction\nin the direction of the GRB.\n\nWe thank the COATLI technical team and the staff of the Observatorio\nAstron��mico Nacional.",
  "circularId": 24287,
  "createdOn": 1556377994000,
  "email": "alan@astro.unam.mx",
  "subject": "GRB 190427A: COATLI Optical Observations",
  "submitter": "Alan M Watson at UNAM  <alan@astro.unam.mx>",
  "eventId": "GRB 190427A"
}