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GCN Circular 14556

GRB 130504A: Swift/UVOT Upper Limits
2013-05-04T13:46:27Z (11 years ago)
Alice Breeveld at MSSL-UCL <>
A. A. Breeveld (MSSL-UCL) and J. R. Cummings (GSFC/UMBC) report on 
behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 130504A 
89s after the BAT trigger (Cummings et al., GCN Circ. 14551), but the 
GRB position is outside the field of view for several exposures. No 
optical afterglow consistent with the XRT position (D'Avanzo et al. GCN 
Circ. 14553) 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 u filter 
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

u_FC               301          551          246         >19.8
white              858         1008          147         >20.5
w1                 680         6058          333         >20.2
m2                 655         7093          356         >20.4
w2                 606         6878          549         >20.8

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 3.22 in the direction of the 
burst (Schlegel et al. 1998).
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