TITLE:   GCN CIRCULAR
NUMBER:  7763
SUBJECT: GRB 80516: Swift/UVOT Observations
DATE:    08/05/22 14:57:08 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) reports on behalf of the Swift/UVOT
team:

      The Swift/UVOT began settled observations the field of GRB 080516
starting 81 s after the BAT trigger (Holland et al., GCN Circ. 7733).
We do not detect the GROND optical afterglow reported by Filgas et al.
(2008a, GCN Circ. 7740) in any of the UVOT data.  The ground-based
position of the afterglow is 10.6 arcsec from the USNO-B1.0 star
638-018182, which has a magnitude of B = 12.  The afterglow is located
in the scattered light halo, and in the coincidence loss pattern of
this star, which makes our photometry somewhat uncertain.

      Upper limits from the coadded data are reported below.

Filter    T_start (s) T_stop  Exposure   Mag    Comment
    v           81     41,277    2950   >21.1    3-sigma UL
    b          560     47,700    2243   >22.2    3-sigma UL
    u          536     47,184    4409   >22.3    3-sigma UL
  uvw1         511     46,278    4913   >22.1    3-sigma UL
  uvm2         486     41,915    3648   >22.1    3-sigma UL
  uvw2         576     40,364    2223   >21.8    3-sigma UL

These upper limits are not corrected for the Galactic extinction along
the line of sight to the source corresponding to a reddening of
E_{B-V} = 0.40 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).