[vsnet-grb-info 16317] GRB 150317A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17598
SUBJECT: GRB 150317A: Swift/UVOT Upper Limits
DATE:    15/03/18 03:49:56 GMT
FROM:    Margaret Chester at PSU  <chester at swift.psu.edu>

M. M. Chester (PSU) and M. H. Siegel (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150317A
126 s after the BAT trigger (Siegel et al., GCN Circ. 17592).
Due to the location of the counterpart (Evans and Goad GCN Circ. 17594, 
Butler et al. GCN Circ. 17595) in the wings of the nearby bright star 
(V~11.2), we cannot report a certain detection.  We therefore provide 
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, as follows:

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

u_FC       126          376          246      >19.6   
v          432         6158          334      >19.2   
b          381         6978          571      >20.4   
u          126         6773          739      >20.2   
w1         481         6568          335      >19.6   
m2         457         6363          255      >19.4   
w2         407         7037          384      >20.0   

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).