[vsnet-grb-info 20681] GRB 180613A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22779
SUBJECT: GRB 180613A: Swift/UVOT Upper Limits
DATE:    18/06/14 19:10:11 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at swift.psu.edu>

S. Sebzda (PSU) and A. Tohuvavohu (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180613A
156 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22769).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 22773)
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

u_FC               156          405          246         >20.4
v                  461        24234         1434         >20.9
b                  411        13230         1022         >99.0
u                  156        18973         2109         >21.8
w1                 510        18472         2212         >21.2
m2                 486        24474         1627         >21.0
w2                1036        23321         1318         >20.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.09 in the direction of the burst
(Schlegel et al. 1998).