[vsnet-grb-info 12670] GRB 121201: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14030
SUBJECT: GRB 121201: Swift/UVOT Detection
DATE:    12/12/02 00:48:41 GMT
FROM:    Paul Kuin at MSSL  <npkuin at gmail.com>

N. P. M. Kuin (MSSL-UCL) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 121201
120 s after the BAT trigger (Yershov et al., GCN Circ. 14025).
A source consistent with the XRT position is detected in the
initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  00:53:52.16 =  13.46732 (deg.)
    Dec (J2000) = -42:56:34.5  = -42.94292 (deg.)
with an estimated uncertainty of 0.62 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits 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              120          270          147         20.3 +/- 0.2
white              558          578           20         19.9 +/- 0.4
white             5689         5888          200         21.3 +/- 0.4
v                  608         1080           59        >19.6
b                  534         1178           58         19.4 +/- 0.2
u                  278          528          125        >24.8
u                 6714         6914          200         20.6 +/- 0.5
w1                 830         6710          432        >21.3
m2                 632         6504          413        >21.1
w2                1036         6094          413        >20.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).