[vsnet-grb-info 19338] GRB 170419A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21035
SUBJECT: GRB 170419A: Swift/UVOT Upper Limits
DATE:    17/04/25 17:28:19 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at swift.psu.edu>

M. H. Siegel (PSU) and B. Sbarufatti (INAF-OAB/PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170419A
592 s after the BAT trigger (Sbarufatti et al., GCN Circ. 21013).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 21015)
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           592          742          147         >21.1
white              592        13376         1194         >22.0
v                  748        19148          594         >19.6
b                  846         7551          313         >20.4
u                  822        23245         1108         >21.0
w1                 797         7141          313         >20.0
m2                 773         6935          274         >19.9
w2                1027        17141          672         >20.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).