[vsnet-grb-info 24029] GRB 191031D: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26128
SUBJECT: GRB 191031D: Swift/UVOT Upper Limits
DATE:    19/11/01 17:00:34 GMT
FROM:    Sam LaPorte at PSU  <sjl5346 at psu.edu>

GRB 191031D: Swift/UVOT Upper Limits

J. D. Gropp (PSU) and V. D'Elia (SSDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 191031D
93 s after the BAT trigger (D'Elia et al., GCN Circ. 26112).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 26117)
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            93          242          147         >20.8
u_FC               306          555          246         >20.2
white               93         6694          575         >21.1
v                  636         5863          294         >19.9
b                  561         6683          471         >20.4
u                  306         6477          697         >20.3
w1                 686         6273          452         >19.8
m2                 661         6067          294         >19.6
w2                 612         5658          294         >19.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).