[vsnet-grb-info 12516] GRB 121017A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13883
SUBJECT: GRB 121017A: Swift/UVOT Upper Limits
DATE:    12/10/18 11:31:14 GMT
FROM:    Alice Breeveld at MSSL-UCL  <aab at mssl.ucl.ac.uk>

A. A. Breeveld (MSSL-UCL) and D. Grupe (PSU) report on behalf of the 
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 121017A 
1142 s after the BAT trigger (Grupe et al., GCN Circ. 13875).
No optical afterglow consistent with the XRT position (Goad et al. GCN 
Circ. 13879) 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          1142         1291          147         >21.1
white             1142         1442          167         >21.2
v                 1298         1492           39         >18.5
b                 1397         1417           19         >19.1
u                 1373         1392           19         >18.6
w1                1347         1367           19         >18.1
w2                1448         1468           19         >18.1

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.44 in the direction of the 
burst (Schlegel et al. 1998).