[vsnet-grb-info 17515] GRB 160127A: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18945
SUBJECT: GRB 160127A: Swift/UVOT Detection
DATE:    16/01/27 20:48:49 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at swift.psu.edu>

M. H. Siegel (PSU) and Amaral-Rogers (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160127A
82 s after the BAT trigger (Amaral-Rogers et al., GCN Circ. 18938).
A fading source consistent with the XRT position
(Evans et al. GCN Circ. 18940)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  15:03:55.76 = 225.98234 (deg.)
   Dec (J2000) = +00:04:22.5  =   0.07291 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: 

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

white (fc)          82          232          147         17.59 +/- 0.04
white              574         2411          342         18.66 +/- 0.08
white             6837         7037          196         20.85 +/- 0.28
v                  624         1942          156         18.46 +/- 0.19
b                  550         1174           58         18.58 +/- 0.16
u (fc)             295          545          246         17.25 +/- 0.05
u                  698         2362          174         18.31 +/- 0.13
u                 6427        19117         1004         20.92 +/- 0.31
w1                 674         1124           58         17.87 +/- 0.20
m2                 824         1966          117         19.07 +/- 0.32
w2                 600         1917          136         19.56 +/- 0.32

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.06 in the direction of the burst
(Schlegel et al. 1998).