[vsnet-grb-info 19012] GRB 170127B: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20554
SUBJECT: GRB 170127B: Swift/UVOT Upper Limits
DATE:    17/01/28 02:36:04 GMT
FROM:    Frank Marshall at GSFC  <femarsha at khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and J. K. Cannizzo (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170127B
114 s after the BAT trigger (Cannizzo et al., GCN Circ. 20540).
No optical afterglow consistent with the enhanced XRT position
(Goad et al. GCN Circ. 20550)
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) exposures and subsequent exposures are:

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

white_FC           114          264          147         >21.2
u_FC               327          576          246         >19.9
white              114         1377          373         >21.0
v                  656         1427           97         >19.4
u                  327          576          246         >19.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).