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GCN Circular 17338

Subject
GRB 150120B: Swift/UVOT Upper Limits
Date
2015-01-21T13:36:09Z (10 years ago)
From
Margaret Chester at PSU <chester@swift.psu.edu>
GRB 150120B: Swift/UVOT Upper Limits

M. M. Chester (PSU) and V. D'Elia (ASDC) report on behalf 
of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150120B
432 s after the BAT trigger (D'Elia et al., GCN Circ. 17314).
No source consistent with the optical afterglow reported by Perley 
(GCN Circ. 17315) and Guidorzi et al. (GCN Circ. 17316) 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           432          582          147         >19.9
white              432         1014          295         >20.5
white             7279         7479          197         >20.7
v                 6254        19560         1278         >20.1
b                 7074        25878          979         >20.9
u                 6869        25353         1999         >21.0
w1                 639         2670          214         >19.6
w1                6664        24440         2164         >21.0
m2                6459        20294         1996         >21.0
w2                1885         3036          124         >19.5
w2                7484        18646         1082         >20.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.20 in the direction of the burst
(Schlegel et al. 1998).
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