TITLE:   GCN CIRCULAR
NUMBER:  29071
SUBJECT: GRB 201216C: Swift/UVOT Upper Limits
DATE:    20/12/17 11:19:46 GMT
FROM:    Samantha Oates at MSSL  <samantha.oates@alumni.ucl.ac.uk>

S. R. Oates (U.Birmingham) and A. P. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201216C
2970 s after the BAT trigger (Beardmore et al., GCN Circ. 29061).
No optical afterglow consistent with the enhanced XRT position
(Osborne et al. GCN Circ. 29067) or the VLT position
(Izzo et al., GCN Circ. 29066) 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          2970         3120          147         >20.0
white             2970         3739          344         >20.7
v                 3950         4150          197         >19.1
b                 3334         3534          197         >19.9
u                 3129         3329          197         >19.3
m2                4154         4331          174         >19.3
w2                3745         3945          197         >19.7

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).