{
  "bibcode": "2017GCN.20393....1K",
  "body": "M. M. Kasliwal (Caltech), S. M. Adams (Caltech), H. Vedantham (Caltech), V.\nBhalerao (IUCAA), S. B. Cenko (NASA/GSFC), R. Quimby (SDSU)\n\nreport on behalf of the GROWTH (Global Relay of Observatories Watching\nTransients Happen) and iPTF (intermediate Palomar Transient Factory)\ncollaborations\n\nWe observed the position of the fast-fading ATLAS17aeu (Tonry et al. LVC\nGCN#20382) with the Large Format Camera on the Palomar 200-inch Hale\nTelescope. At 2017-01-07 08:05:33 UTC, we found that ATLAS17aeu had faded\nfurther to  i=21.9 +/- 0.3 mag (AB mags, calibration wrt SDSS).\n\nIf we fit a power law to the decay, the best-fit slope is 1.1 +/- 0.2  and\nbest-fit t_zero is 57758.322 +/- 0.043 (i.e. 21.5 hr after GW trigger, LVC\nGCN#20364). We caution that we have not corrected for the filter\ndifferences between ATLAS and LFC. Incidentally, this t_zero is consistent\nwith GRB070105A reported by POLAR (GCN#20387) and detected by ASTROSAT\n(GCN#20389). The hypothesis that this is the afterglow of the GRB appears\nconsistent with the X-ray detection reported by Swift (Evans et al. LVC\nGCN#20390).",
  "circularId": 20393,
  "createdOn": 1483807474000,
  "email": "mansi@astro.caltech.edu",
  "subject": "LIGO/Virgo G268556: Palomar 200-inch detects ATLAS17aeu, possible afterglow of GRB070105A?",
  "submitter": "Mansi M. Kasliwal at Caltech  <mansi@astro.caltech.edu>",
  "eventId": "LIGO/Virgo G268556"
}