[AAVSO-HEN] GRB 090607: Swift/UVOT Upper Limits

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  9495
SUBJECT: GRB 090607: Swift/UVOT Upper Limits
DATE:    09/06/07 16:42:02 GMT
FROM:    Peter Curran at MSSL  <pac at mssl.ucl.ac.uk>

P.A. Curran (UCL-MSSL) and F. Marshall (NASA/GSFC)
report on behalf of the Swift/UVOT team:


The Swift/UVOT began settled observations of the field of GRB 090607
75 s after the BAT trigger (Marshall et al., GCN Circ. 9491). No optical 
afterglow consistent with the XRT position (Marshall et al., GCN Circ. 
9491) is detected in the initial UVOT exposures. Preliminary 3-sigma 
upper limits using the UVOT photometric system (Poole et al. 2008, 
MNRAS, 383, 627) for the first finding chart (FC) exposure and 
subsequent exposures are:


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

uvw1           12715       13943       1209         >20.8
u              75          1233        1140         >21.2
v              11448       12707       1239         >20.4


The values quoted above 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).