[vsnet-grb-info 23029] GRB 190719C: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25128
SUBJECT: GRB 190719C: Swift/UVOT Upper Limits
DATE:    19/07/20 16:32:27 GMT
FROM:    Paul Kuin at MSSL  <npkuin at gmail.com>

N. P. M. Kuin (UCL-MSSL) and E. Ambrosi (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190719C
71 s after the BAT trigger (Ambrosi et al., GCN Circ. 25106).
No optical afterglow consistent with the XRT position 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            71          221          147         >20.6
u_FC               283          533          246         >20.6
white               71          756          186         >20.8
v                  613          807           39         >18.7
b                  538          732           39         >19.9
u                  283          706          265         >20.5
w1                 662          856           39         >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).

The upper limits are consistent with the faint candidate
afterglow reported by Malesani et al. (GCN Circ. 25110).