GCN Circular 23626

N. P. M. Kuin (UCL-MSSL) and E. Sonbas (Adiyaman Univ.)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190106A
90 s after the BAT trigger (Sonbas et al., GCN Circ. 23615
Not found
 
 
).
A source consistent with the XRT position (Goad et al. GCN Circ. 23619
Not found
 
 
)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  01:59:31.16 =  29.87985 (deg.)
    Dec (J2000) = +23:50:43.9  =  23.84552 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

The source was also detected by MASTER (Yurkov et al, GCN Circ.
23614
Not found
 
 
,23616
Not found
 
 
),
MITSuME (Itoh et al, GCN Circ. 23617
Not found
 
 
), GMG (Mao et al, GCN Circ. 23618
Not found
 
 
),
TSHAO (Reva et al, GCN Circ. 23620
Not found
 
 
), GWAC-F60B (Xin et al, GCN Circ. 23622
Not found
 
 
),
Xinglong (Zhu et al, GCN Circ. 23623
Not found
 
 
) who report a redshift of z~0.896 and
Bassano Bresciano Observatory (Quadri et al, GCN Circ. 23624
Not found
 
 
).

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               90          240          147         16.64 +/- 0.03
v                  633          653           20         16.54 +/- 0.16
b                  559          579           20         16.70 +/- 0.09
u                  304          553          246         15.97 +/- 0.03
w1                 682          702           20         17.36 +/- 0.29

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.09 in the direction of the burst
(Schlegel et al. 1998).