GCN Circular 12032
Subject
Swift/UVOT observations of GRB110520A
Event
Date
2011-05-21T16:10:32Z (15 years ago)
From
Massimiliano de Pasquale at MSSL-UCL <mdp@mssl.ucl.ac.uk>
M. De Pasquale (MSSL-UCL) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 110520A
104 s after the BAT trigger (De Pasquale et al., GCN Circ. 12020).
No optical afterglow consistent with the enhanced XRT position (Osborne et
al., GCN Circ. 12027) or at the position of the NOT and WHT sources
(Schulze et al., GCN Circ 12025; Levan et al. GCN Circ 12026) is detected
in the initial and in the summed UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 104 253 147 >21.1
u_FC 316 565 246 >20.4
white 104 30973 3040 >22.9
v 645 23608 2083 >21.0
b 571 36751 2946 >22.1
u 316 42529 3178 >21.8
w1 694 41871 2965 >21.8
m2 842 40964 2262 >21.8
w2 621 19418 1911 >22.0
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).