{
  "bibcode": "2021GCN.30534....1W",
  "body": "Alan M. Watson (UNAM), Eleonora Troja (GSFC), Nat Butler (ASU), Alexander\nKutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox\n(STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Enrico Ramirez-Ruiz\n(UCSC), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Harvey Moseley\n(GSFC), Rosa L. Becerra (UNAM), Simone Dichiara (UMD), and Oc��lotl L��pez (UNAM)\nreport:\n\nWe observed the field of candidate short GRB 210726A (Bernardini et al., GCN\nCirc., 30523) with the Reionization and Transients Infrared Camera (RATIR) on\nthe 1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on\nSierra San Pedro M��rtir from 2021/07 27.16 to 2021/07 27.22 UTC (8.24 to 9.65\nhours after the BAT trigger), obtaining a total of 1.09 hours exposure in the r\nand i bands.\n\nFor a source within the enhanced Swift-XRT error circle (Osborne et al., GCN\nCirc., 30524), in comparison with the SDSS DR9 catalog, we obtain the following\nupper limits (3-sigma):\n\n  r\t> 23.0\n  i\t> 22.7\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.\n\nWe note that the SDSS galaxy J125309.63+191127.2 is 3.1 arcsec from the enhanced\nXRT position and just outside the error circle. In our observations, it has \nr = 22.2 +/- 0.2 and i = 22.2 +/- 0.2, in agreement with the cataloged values.\nThe cataloged photometric redshift is z = 0.35 +/- 0.15. The probability of a\nchance alignment is approximately 3%. Given this low probability, we suggest\nthat this source might be the host galaxy.\n\nSince this GRB appears to be potentially both short and low-redshift, we\nencourage further observations.\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro M��rtir.",
  "circularId": 30534,
  "createdOn": 1627402465000,
  "email": "alan@astro.unam.mx",
  "subject": "GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy",
  "submitter": "Alan M Watson at UNAM  <alan@astro.unam.mx>",
  "eventId": "GRB 210726A"
}