[vsnet-grb-info 20152] GRB 171212A/Swift J1935.7+2036: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22248
SUBJECT: GRB 171212A/Swift J1935.7+2036: Swift/UVOT Upper Limits
DATE:    17/12/12 22:16:30 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld at ucl.ac.uk>

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

The Swift/UVOT began settled observations of the field of GRB 171212A 99 
s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22243).
No optical afterglow consistent with the enhanced XRT position (Evans et 
al., GCN Circ. 22245) 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            99          249          147         >20.3
u_FC               257          507          246         >19.8
white               99         5510          383         >20.8
v                  588         5921          235         >19.0
b                  513         6581          275         >20.1
u                  257         6536          468         >20.1
w1                 638         6331          236         >19.5
m2                5926         6125          197         >19.3
w2                 738         5716          216         >19.5

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 7.95 in the direction of the 
burst (Schlegel et al. 1998).