[vsnet-grb-info 13772] GRB130807A: Swift/UVOT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15086
SUBJECT: GRB130807A: Swift/UVOT observations
DATE:    13/08/08 19:53:04 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <m.depasquale at ucl.ac.uk>

M. De Pasquale (UCL-MSSL) and A. Melandri (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 130807A
145 s after the BAT trigger (Melandri et al., GCN Circ. 15082).
No optical source consistent with the XRT position (Melandri et al.,
GCN Circ. 15085) is detected in the 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 summed exposures are:

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

white_FC          3572         3722          147         >20.3
white             3572         5573          541         >21.1
v                 4348         5984          393         >19.3
b                 3732         5369          393         >20.3
u_FC               145          311          163         >19.7
u                  145         5164          360         >19.9
w1                4759         4959          197         >19.6
m2                4552         6078          284         >19.7
w2                4143         5780          393         >20.2

The magnitudes in the table are not corrected for the strong Galactic
extinction corresponing to the reddening of E(B-V) = 2.03 in the
direction of the burst (Schlegel et al. 1998).