[vsnet-grb-info 18522] GRB 161001A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19970
SUBJECT: GRB 161001A: Swift/UVOT Upper Limits
DATE:    16/10/01 11:40:49 GMT
FROM:    Paul Kuin at MSSL  <npkuin at gmail.com>

N. P. M. Kuin (UCL-MSSL) 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 161001A
68 s after the BAT trigger (Page et al., GCN Circ. 19967). No optical
afterglow consistent with the XRT position (Osborne et al. GCN Circ.
19969) 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            68          218          147         >20.8
u_FC               281          530          246         >20.2
white               68         1183          353         >20.4
v                  611         1232           78         >19.1
b                  536         1158           58         >19.1
u                  281         5994          395         >20.2
w1                 661         1282           78         >19.2
m2                 636         1257           78         >19.2
w2                1016         1208           39         >19.2

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).