{
  "bibcode": "2018GCN.23492....1W",
  "body": "Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), William\nH. Lee (UNAM), Margarita Pereyra (UNAM), Carlos Rom��n-Z����iga (UNAM),\nAlexander Kutyrev (GSFC), and Eleonora Troja (GSFC), report:\n\nWe observed the field of GRB 181201A (Mereghetti et al., GCN 23469) with\nthe COATLI 50-cm telescope and interim imager at the Observatorio\nAstron��mico Nacional on the Sierra de San Pedro M��rtir\n(http://coatli.astroscu.unam.mx) from 2018-12-03 01:30:45 to 04:14:39\n(from 46.9 to 49.6 hours after the trigger), obtaining a total of 1.5\nhours of exposure in the w filter.\n\nWe continue to detect the optical counterpart reported by Podesta et al.\n(GCN Circ. 23470) at w = 18.77 +/- 0.02.\n\nThe counterpart has faded by about 1 magnitude since our previous\nobservations (Watson et al., GCN 23481). Further observations are\nplanned.\n\nOur w magnitudes are calibrated against the USNO-B1 catalog (adjusted to\nan approximate AB system) and are not corrected for Galactic extinction\nin the direction of the GRB.\n\nWe thank the COATLI technical team (Fernando ��ngeles, Oscar Chapa,\nSalvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosal��a Langarica,\nFernando Quir��s, and Carlos Tejada) and the staff of the Observatorio\nAstron��mico Nacional.",
  "circularId": 23492,
  "createdOn": 1543821164000,
  "email": "alan@astro.unam.mx",
  "subject": "GRB 181201A: Further COATLI Optical Monitoring",
  "submitter": "Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>",
  "eventId": "GRB 181201A"
}