[vsnet-grb-info 14061] GRB 131024A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15375
SUBJECT: GRB 131024A: Swift/UVOT Upper Limits
DATE:    13/10/25 03:21:43 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at swift.psu.edu>

M. H. Siegel (PSU) and J. L. Racusin (NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131024A
137 s after the BAT trigger (Racusin et al., GCN Circ. 15365).
No optical afterglow consistent with the enhanced XRT position
(Osborne et al., GCN Circ. 15367) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white (fc)         136          286          147         >20.63
white              136         1542          392         >21.69
v                  624         1592          116         >18.91
b                  550         1517           97         >19.75
u (fc)             294          544          245         >19.99
u                  294         1492          569         >20.49
uvw1               673         1468           97         >19.15
uvm2               648         1606          106         >18.99
uvw2               600         1567          116         >19.48

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).