GCN Circular 22275
Subject
GRB 171222A: Swift/UVOT Upper Limits
Event
Date
2017-12-23T14:09:12Z (8 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and J. L. Racusin (NASA/GSFC) report on
behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 171222A
176 s after the BAT trigger (Racusin et al., GCN Circ. 22265). No
optical afterglow consistent with the enhanced XRT position (Osborne
et al. GCN Circ 22266) or the NOT position (Perley et al., GCN Circ
22269) is detected in the initial UVOT exposures.
The optical afterglow was detected however by Perley et al. (GCN Circ
22269), Tyurina et al. (GCN Circ. 22273), and a redshift was reported
by de Ugarte Postigo (GCN Circ. 22272).
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
u_FC 176 426 246 >20.6
u 176 1026 393 >20.3
b 432 1795 175 >20.3
v 482 1846 175 >19.2
uvw1 531 1895 175 >19.4
uvm2 506 1870 175 >19.3
uvw2 458 1821 175 >19.6
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).