TITLE:   GCN CIRCULAR
NUMBER:  19631
SUBJECT: GRB 160630A: Swift/UVOT Upper Limits
DATE:    16/06/30 15:22:22 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

S. J. LaPorte (PSU) and H. A. Krimm (CRESST/GSFC/USRA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160630A
87 s after the BAT trigger (Krimm et al., GCN Circ. 19624).
No optical afterglow consistent with the enhanced XRT position
(Goad et al., GCN Circ 19626) or the optical/IR position
(Kann et al. GCN Circ. 19625) 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            87          237          147         >20.6
u_FC               300          550          246         >19.9
white               87         6366          530         >21.7
v                  630         6777          439         >20.2
b                  555         6161          236         >20.5
u                  300         5956          462         >20.6
w1                 680         7042          290         >19.7
m2                 655         6982          432         >20.9
w2                 606         6572          255         >19.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.48 in the direction of the burst
(Schlegel et al. 1998).