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GCN Circular 22299

Subject
GRB 180102A: Swift/UVOT Upper Limits
Date
2018-01-03T12:37:47Z (7 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180102A 74 
s after the BAT trigger (Page et al., GCN Circ. 22292).
No optical afterglow consistent with the XRT position (Beardmore et al. 
GCN Circ. 22294) 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            74          224          147         >20.8
u_FC               286          535          246         >19.9
white               74         7508          824         >21.3
v                  616         6484          352         >19.3
b                  541         7303          529         >20.3
u                  286         7098          717         >20.4
w1                 665         6893          529         >20.1
m2                 640         6688          350         >19.7
w2                 591         7692          528         >20.1

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.01 in the direction of the 
burst (Schlegel et al. 1998).
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