{
  "bibcode": "2017GCN.20485....1G",
  "body": "Zach Golkhou (ASU), Nat Butler (ASU), Neil Gehrels (GSFC), Alexander\nKutyrev (GSFC), William H. Lee (UNAM), Eleonora Troja (GSFC), and Alan M.\nWatson (UNAM) report:\n\nWe observed a number of iPTF candidates (Kasliwal et al. LVC GCN#20398)\nwith the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)\non the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico\nNacional on Sierra San Pedro M��rtir from 2017/01 11.28--11.30 UTC (6.85\ndays since the GW trigger; Shawhan et al. LVC GCN #20364) and again from\n2017/01 12.44--12.46 UTC.\n\nAt positions consistent with each iPTF source position, we report riZY\nphotometry for the probable host galaxy from the first epoch. In comparison\nwith the SDSS DR9 and 2MASS catalogs, we obtain:\n\n# Source   r                   (dt_r)  i                     (dt_i)   Z\n             (dt_Z)   Y                (dt_Y)\niPTF17ce 19.84+/-0.04 (0.36) 18.92+/-0.02 (0.36) 18.37+/-0.02 (0.07)\n18.35+/-0.03 (0.07)\niPTF17ck 18.17+/-0.01 (0.71) 17.59+/-0.01 (0.71) 17.63+/-0.01 (0.15)\n17.33+/-0.01 (0.15)\niPTF17dz   ...                          19.09+/-0.01 (0.51) 19.30+/-0.03\n(0.22) 19.23+/-0.04 (0.22)\niPTF17ef 19.18+/-0.02 (1.07) 18.92+/-0.02 (1.07) 18.86+/-0.03 (0.22)\n18.59+/-0.02 (0.22)\niPTF17ei 16.77+/-0.01 (1.38) 16.37+/-0.01 (1.38) 16.17+/-0.01 (0.29)\n15.97+/-0.01 (0.29)\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the source direction. Exposure times (dt) are reported in\nhours.\n\nWe find no evidence for variation in flux at >2-sigma confidence from an\nimage subtraction analysis between our two epochs.\n\nWe thank the staff of the Observatorio Astron��mico Nacional in San Pedro\nM��rtir.",
  "circularId": 20485,
  "createdOn": 1484889034000,
  "email": "golkhou@gmail.com",
  "subject": "LIGO/Virgo G268556: RATIR Observation of iPTF Candidates",
  "submitter": "V. Zachary Golkhou at ASU/SESE--RATIR  <golkhou@gmail.com>",
  "eventId": "LIGO/Virgo G268556"
}