[vsnet-grb-info 20869] GRB 180715A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22967
SUBJECT: GRB 180715A: Swift/UVOT Upper Limits
DATE:    18/07/19 15:46:40 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at swift.psu.edu>

M. H. Siegel (PSU) and T. N. Ukwatta (LANL)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180715A
4312 s after the BAT trigger (Ukwatta et al., GCN Circ. 22947).
No optical afterglow consistent with the BAT position (Ukwatta et al., GCN
Circ. 22951) 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          4312         4462          147         >20.6
white             4312         5695          344         >21.0
v                 4469         4669          197         >19.1
b                 5290         5490          197         >20.1
u                 5085         5284          197         >19.8
w1                4879         5079          197         >19.5
m2                4674         4874          197         >19.7
w2                5701         5726           25         >18.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.13 in the direction of the burst
(Schlegel et al. 1998).