GCN Circular 12891
Subject
GRB 120121A: Swift/UVOT Upper Limits
Event
Date
2012-01-21T20:11:24Z (14 years ago)
From
Frank Marshall at GSFC <femarsha@khamseen.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) 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 120121A
124 s after the BAT trigger (Page et al., GCN Circ. 12885).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 12888)
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 124 273 147 >20.2
u_FC 336 585 246 >19.7
white 124 6777 673 >21.1
v 664 7188 510 >18.9
b 591 13219 1160 >20.2
u 336 18998 2078 >20.2
w1 714 18281 2108 >20.4
m2 16474 17374 886 >20.1
w2 1020 23198 1298 >21.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.87 in the direction of the burst
(Schlegel et al. 1998).