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GCN Circular 23673

Correction to GCN Circular 23663: GRB 190109A: Swift UVOT Upper Limits
2019-01-11T15:01:41Z (5 years ago)
Kira Simpson at PSU <>
The values for magnitude UVOT's white filter were listed as 99th magnitude
in the previous circular and have been corrected here.

GRB 190109A: Swift/UVOT Upper Limits

K. K. Simpson (PSU) and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190109A
181 s after the BAT trigger (Gropp et al., GCN Circ. 23642).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 23644)
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           181          331          147         >21.60
white              181        12997         1291         >20.27
v                  670         6867          490         >16.8
b                  596        18739         1727         >18.6
u                  340        24226         2551         >17.5
w1                 720        23954         2223         >17.4
m2                 695        23048         1357         >18.1
w2                 646         6662          491         >17.9

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).
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