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GCN Circular 24159

GRB 190422A: Swift/UVOT Upper Limits
2019-04-23T17:30:19Z (5 years ago)
Kira Simpson at PSU <>
GRB 190422A: Swift/UVOT Upper Limits

K. K. Simpson (PSU) and M. J. Moss (George Washington University)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190422A
532 s after the BAT trigger (Moss et al., GCN Circ. 24147).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 24151)
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           532          682          147         >18.8
white              532         7906          647         >18.8
v                  689         6879          352         >17.2
b                  788         7700          352         >18.3
u                  763         7495          352         >18.9
w1                 738         7289          352         >19.1
m2                 713         7084          352         >19.1
w2                 838         7995          438         >19.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.58 in the direction of the burst
(Schlegel et al. 1998).
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