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GCN Circular 18405

Subject

GRB 151006A: Swift/UVOT Upper Limits

Date

2015-10-06T19:03:04Z (9 years ago)

From

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

A. A. Breeveld (UCL-MSSL) and D. Kocevski (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 151006A 36 
s after the BAT trigger (Kocevski et al., GCN Circ. 18398Not found
 
 
).
No optical afterglow consistent with the XRT position (Goad et al. GCN 
Circ. 18403Not found
 
 
) 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            58          208          147         >20.7
u_FC               271          521          246         >19.9
white               58         6351          520         >21.4
v                   36         6754          437         >19.8
b                  527         6146          236         >20.3
u                  271         5941          442         >20.3
w1                5537         5736          197         >19.8
m2                 625         5531          235         >19.7
w2                 577         6557          432         >20.4

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.24 in the direction of the 
burst (Schlegel et al. 1998).