[vsnet-grb-info 19831] GRB 170712B: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21881
SUBJECT: GRB 170712B: Swift/UVOT Upper Limits
DATE:    17/09/14 02:44:20 GMT
FROM:    Sam LaPorte at PSU  <sjl5346 at psu.edu>

GRB 170912B: Swift/UVOT Upper Limits

S. J. LaPorte (PSU) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170912B
60 s after the BAT trigger (LaPorte et al., GCN Circ. 21864).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 21868)
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      57          207        147       >20.26  
white         58          1024       332       >20.72
v             600         1074       58        >18.08    
b             525         718        38        >18.76 
u             269         1144       299       >19.67
uvw1          649         1124       58        >18.24  
uvm2          624         1099       58        >18.12   
uvw2          575         1050       58        >18.39  


The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 5.05 in the direction of the burst
(Schlegel et al. 1998).