GCN Circular 9717
Subject
GRB090726: Swift/UVOT observations
Date
2009-07-27T16:01:04Z (15 years ago)
From
Wayne Landsman at GSFC/SSAI <wayne.b.landsman@nasa.gov>
W.B. Landsman (NASA/GSFC) and K.Page (U. Leicester)report on behalf of
the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 090726,
3610s after the BAT trigger (Page et al., GCN Circ. 9706), and the
afterglow first reported by Moskvitin et al., (GCN Circ. 9709) is
detected in the UVOT white, v, and b filters.
The initial magnitudes and upper limits are as follows:
Filter T_start(s) Exp(s) Mag
white 3610 147 20.62 � 0.18
white 4179 197 21.36 � 0.29
v 4589 197 19.98 � 0.36
b 3974 197 20.80 � 0.44
u 3769 197 >20.9 (3 sigma)
uvw1 5000 197 >20.6 (3 sigma)
uvm2 4794 197 >20.6 (3 sigma)
uvw2 4385 197 >21.0 (3 sigma)
The nondetections in the u and UV filters are consistent with the
redshift of z= 2.71 reported by Fatkhullin et al (GCN 9712)
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.045 in the direction of the burst.
The photometry is on the UVOT photometric system described in Poole et
al. (2008, MNRAS, 383, 627).