{
  "bibcode": "2014GCN.15894....1S",
  "body": "M. H. Siegel (PSU), F. E. Marshall (NASA/GSFC) and A. P. Beardmore (U. Leicester)\nreport on behalf of the Swift/UVOT team:\n\nSwift/UVOT started observations of GRB140226A/iPTF14yb (Cenko et al., GCN Circ. \n15833) 25718 s after the IPN trigger (Hurley et al., GCN Circ. 15888).\nNo optical counterpart is detected at the position of the iPTF or\nXRT positions (Beardmore et al., GCN Circ 15884) in summed\nexposures.\n\nPreliminary 3-sigma upper limit using the UVOT photometric system \n(Breeveld et al al. 2011, AIP Conf. Proc. 1358, 373) is:\n\nFilter   T_start (s)  T_stop (s)  Exp(s)     Mag\n\nuvm2      25718        43672      2180     >21.24\nv        124093       136265      4877     >20.96\nv        147705       154552      1822     >20.54\n\nNo correction has been made for the expected Galactic extinction \ncorresponding to E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).",
  "circularId": 15894,
  "createdOn": 1393605557000,
  "email": "siegel@swift.psu.edu",
  "subject": "GRB 140226A/iPTF14yb: Swift/UVOT Observations",
  "submitter": "Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>",
  "eventId": "GRB 140226A"
}