{
  "subject": "GRB 070808: Swift/UVOT upper limits",
  "eventId": "GRB 070808",
  "bibcode": "2007GCN..6730....1M",
  "createdOn": 1186698091000,
  "circularId": 6730,
  "submitter": "Frank Marshall at GSFC  <marshall@milkyway.gsfc.nasa.gov>",
  "email": "marshall@milkyway.gsfc.nasa.gov",
  "body": "F.E. Marshall (NASA/GSFC) and J.R. Cummings (NASA/UMBC)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT observed the field of GRB 070808 starting 119 s after\nthe BAT trigger (Cummings et al., GCN Circ. 6718).  We do not find a source\nin any of the UVOT observations inside the refined XRT error circle\n(Starling and Cummings, GCN Circ. 6725). The 3-sigma upper limits for detecting\na source in the first finding chart (FC) exposure and co-added frames are:\n\nFilter            T_start(s)   T_stop(s)     Exp(s)     Mag (3-sigma UL)\n\nwhite (FC)        119          218           98         >20.6\nwhite             119          7539          628        >20.9\nv                 225          6515          1051       >20.4\nb                 704          7334          461        >20.5\nu                 680          7129          490        >20.6\nuvw1              655          6925          490        >20.3\nuvm2              783          6720          452        >20.9\nuvw2              734          7625          353        >20.8\n\nThe values quoted above are not corrected for the expected Galactic\nextinction corresponding to a reddening of E(B-V) = 0.02 mag in\nthe direction of the burst (Schlegel et al. 1998)."
}