{
  "bibcode": "2015GCN.18032....1W",
  "body": "Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William \nH. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), \nJ. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara \n(ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico \nRamirez-Ruiz (UCSC), Jos� A. de Diego (UNAM), Leonid Georgiev (UNAM), \nJes�s Gonz�lez (UNAM), Carlos Rom�n-Z��iga (UNAM), Neil Gehrels (GSFC), \nand Harvey Moseley (GSFC) report:\n\nWe observed the field of GRB 150716A (Kocevski et al., GCN 18027) with the \nReionization and Transients Infrared Camera (RATIR; www.ratir.org) on the \n1.5m Harold Johnson Telescope at the Observatorio Astron�mico Nacional on \nSierra San Pedro M�rtir from 2015/07 17.16 to 2015/07 17.46 UTC (20.69 to \n27.82 hours after the BAT trigger), obtaining a total of 4.31 hours \nexposure in the r and i bands.\n\nIn these observations, the source reported by Watson et al. (GCN 18028) is \ndetected with\n\nr 20.43 � 0.02\ni 19.89 � 0.02\n\nThese magnitudes are in the AB system and are not corrected for Galactic \nextinction in the direction of the GRB.\n\nWhile these formal errors would suggest a slight fading compared to the \nfirst night, in a crowded field such as this one, the real errors in the \nphotometry are likely to be much larger than these formal errors of 0.02 \nmag. We feel that there is no strong evidence for fading. Also, as noted \nby Cenko & Perley (GCN 18029), this source is significantly outside the \nenhanced XRT error region reported by Sbarufatti et al. (GCN 18030). We \ntherefore conclude that it is not the afterglow.\n\nWe see no evidence for the source reported by Cenko & Perley (GCN 18029) \nin any of our images. However, this is not unexpected, since our images \nhave significantly worse image quality than theirs.\n\nWe thank the staff of the Observatorio Astron�mico Nacional in San Pedro \nM�rtir.",
  "circularId": 18032,
  "createdOn": 1437158692000,
  "email": "alan@astro.unam.mx",
  "subject": "GRB 150716A: Continued RATIR Optical Observations",
  "submitter": "Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>",
  "eventId": "GRB 150716A"
}