TITLE:   GCN CIRCULAR
NUMBER:  36870
SUBJECT: GRB 240712A: Swift/UVOT Upper Limits
DATE:    24/07/15 15:26:44 GMT
FROM:    Paul Kuin at MSSL <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and C. Salvaggio (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240712A
141 s after the BAT trigger (Salvaggio et al., GCN Circ. 36851).
No optical afterglow consistent with the XRT position in GCN Circ
36851 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           141          290          147         >20.2
u_FC               299          549          246         >19.9
white              141         1550          392         >21.0
v                  629         5288          179         >19.0
b                  555         1525           97         >20.0
u                  299         1500          324         >20.3
w1                 678         1476           97         >19.2
m2                 653         1451           97         >18.7
w2                 604         5200          313         >19.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.996 in the direction of the burst
(Schlegel et al. 1998).