{
  "bibcode": "2008GCN..8192....1H",
  "body": "S. T. Holland (CRESST/USRA/GSFC) & M. C. Stroh (PSU) report on behalf\nof the Swift/UVOT team:\n\n       The Swift/UVOT observed the field of GRB 080905B starting 94 s\nafter the BAT trigger (Stroh et al., 2008, GCNC. 8182).  Settled\nobservations started at T + 113 s.  We detect the optical afterglow\n(Stroh et al., GCNC 8182) in the v and white filters at the\nUVOT-enhanced location of the XRT afterglow (Osborne, et al., 2008,\nGCNC 8089).  There is an uncertain detection in the b filter.  The\nrefined UVOT source position is\n\n  RA (J2000.0) =  20:06:57.89\nDec (J2000.0) = -62:33:47.0\n\nwith an estimated uncertainty of 0.7 arcsec (radius, 90%\nconfidence).  We note that the afterglow is slightly blended with the\nUSNO-B1.0 star 274-094527, which makes it dificult to confirm the\ndetection in the b band.\n\n     Magnitudes and upper limits are reported below.\n\nFilter   TSTART   TSTOP     Exposure     Mag   Err  Comment\n  white      113     213           98   18.70  0.09\n    v        219     619          394   16.60  0.07\n    b        699    6033          206   19.49  0.15  uncertain detection\n    u        674    5828          216  >20.7         3-sigma upper limit\n   uvw1      650    5623          197  >20.3         3-sigma upper limit\n   uvm2     5218    5418          197  >19.9         3-sigma upper limit\n   uvw2      729    6445          197  >20.5         3-sigma upper limit\n\nThe above magnitudes are not corrected for the Galactic extinction\ncorresponding to a reddening of E_{B-V} = 0.05 mag (Schlegel et al.,\n1998, ApJS, 500, 525).  The photometry is on the UVOT photometric\nsystem described in Poole et al. (2008, MNRAS, 383,627).  The possible\ndetection in the b filter, coupled with the non-detections in the u,\nuvw1, uvm2, and uvw2 filters, are consistent with a redshift of\napproximately z < 3.3.  The power-law decay index in the v band\nbetween 763 and 6505 s is -0.88.",
  "circularId": 8192,
  "createdOn": 1220748211000,
  "email": "sholland@milkyway.gsfc.nasa.gov",
  "subject": "GRB 080905B: Refined UVOT Analysis",
  "submitter": "Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 080905B"
}