[vsnet-grb-info 11041] GRB 111018A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12459
SUBJECT: GRB 111018A: Swift/UVOT Upper Limits
DATE:    11/10/19 12:59:31 GMT
FROM:    Alice Breeveld at MSSL-UCL  <aab at mssl.ucl.ac.uk>

A. A. Breeveld (MSSL-UCL) and F. E. Marshall (NASA/GSFC) report on 
behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 111018A 
132 s after the BAT trigger (Marshall et al., GCN Circ. 12450). No 
optical afterglow consistent with the refined XRT position (Goad et 
al., GCN Circ. 12453) is detected in the initial UVOT exposures. 
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) 
exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           132          282          147         >21.1
white              132         7508          653         >21.8
v                  462        12028          673         >20.2
b                  388         6000          333         >20.9
u                  291         5794          329         >20.6
uvw1               512         5590          314         >20.4
uvm2               487         5384          333         >20.2
uvw2               438        11672         1040         >21.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 2.16 in the direction of the burst
(Schlegel et al. 1998).