[vsnet-grb-info 5846] GRB 080319A: UVOT Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7495
SUBJECT: GRB 080319A: UVOT Observations
DATE:    08/03/21 11:33:57 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland at milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/GSFC/USRA) and C. Pagani (PSU) report on behalf
of the Swift/UVOT team:

      The Swift/UVOT observed the field of GRB 080319A starting 542 s
after the BAT trigger (Pagani et al., GCN Circ. 7426).  We detect the
optical afterglow in the white filter at the location of the P60
source (Cenko, 2008, GCN Circ. 7429).

Magnitudes and upper limits are reported below.

Filter    T_start (s) T_stop  Exposure      Mag  Err  Comment
    v          669       1544      432     >20.7       3-sigma UL
    b          767       1480       29     >19.8       3-sigma UL
    u          743       1618       58     >19.9       3-sigma UL
  white        562        662       98      21.1  0.3
               875        975       98     >21.4       3-sigma UL

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0 .02 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT flight system
described in Poole et al. (2008, MNRAS, 383,627).  No early-time upper
limits are available for the uvw1, uvm2, and uvw2 filters due to the
lack of data resulting from the slew to GRB 080319B, which occurred 25
minutes after GRB 080319A.