[vsnet-grb-info 17776] GRB 160321A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19217
SUBJECT: GRB 160321A: Swift/UVOT Upper Limits
DATE:    16/03/22 15:04:48 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15 at ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) and M. Stamatikos (OSU/NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160321A
115 s after the BAT trigger (Stamatikos et al., GCN Circ. 19211).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 19213)
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           115          265          147         >20.4
u_FC               273          523          246         >19.7
white              115         6458          546         >21.1
v                  603         6870          452         >19.5
b                  529         6253          255         >20.1
u                  273        12683          570         >20.1
w1                 652        12607         1141         >20.2
m2                 627        11700         1205         >20.1
w2                 579         6664          452         >19.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.75 in the direction of the burst
(Schlegel et al. 1998).