GCN Circular 18384

Subject

GRB 151001B: Swift/UVOT Upper Limits

Event

Date

2015-10-02T18:50:46Z (11 years ago)

From

Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and H. A. Krimm (CRESST/GSFC/USRA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 151001B 
148 s after the BAT trigger (Krimm et al., GCN Circ. 18374Loading...
 
 ).
No optical afterglow consistent with the XRT position (Evans et al. GCN 
Circ. 18377Loading...
 
 ) 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           148          298          147         >20.6
white              148         6765          805         >21.8
u_FC               307          557          246         >19.9
v                  636         7175          529         >20.2
b                  563         6561          333         >20.9
u                  307        11107          685         >20.7
w1                 686         7585          510         >20.2
m2                 661         7380          529         >20.2
w2                 613         6970          529         >20.6

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 1.71 in the direction of the 
burst (Schlegel et al. 1998).