[vsnet-grb-info 8277] GRB 090814A: Swift/UVOT Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9802
SUBJECT: GRB 090814A: Swift/UVOT Observations
DATE:    09/08/14 13:52:07 GMT
FROM:    Peter Curran at MSSL  <pac at mssl.ucl.ac.uk>

P.A. Curran (MSSL-UCL), T. N. Ukwatta (GSFC/GWU), report on behalf of
the Swift/UVOT team:


The Swift/UVOT began settled observations of the field of GRB 090814A
170s after the BAT trigger (Ukwatta  et al., GCN 9793). The proposed
optical counterpart (Updike et al. , GCN 9794) is marginally detected in
the u and white UVOT exposures. No optical afterglow consistent with the
enhanced XRT position (Beardmore et al., GCN 9796)  is detected in the
other UVOT exposures.


Preliminary magnitudes and 3-sigma upper limits using the UVOT
photometric system (Poole et al. 2008, MNRAS, 383, 627) for for the
first finding charts (FC) and subsequent exposures are:

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

u       328	   577          246	> 20.16 (FC)
wh      170	   319          147	> 20.70 (FC)				

u       328	   8144         834	21.05 +/- 0.35
b       584	   8340         599	> 21.30
v       658	   7528         607	> 20.18		
w1      708	   7939         529	> 20.66
m2      683	   7733         529	> 20.5
w2      708	   7939         607	> 20.81				
wh      170	   7117         699	21.54 +/- 0.27


The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.078 in the direction of the burst
(Schlegel et al. 1998).