GCN Circular 6546
Subject
Swift/UVOT observations of GRB070616
Event
Date
2007-06-17T02:38:44Z (18 years ago)
From
Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>
M. De Pasquale (MSSL/UCL), R. Starling (Univ. Leicester)
and P. Schady (MSSL/UCL) report, on the behalf ot the Swift
UVOT team:
  The Swift UVOT telescope began its White filter finding
chart exposure of GRB070616 (Starling et al., GCN circ 6542)
144 seconds after the trigger. The XRT position lies on
a bright object, listed in the USNO-B1.0 catalogue, therefore
we caution that this source strongly affects the photometry.
In the XRT error circle we do not detect any optical
afterglow. We derive the following 3 sigma upper limits:
Filter  Time after trigger (s)  Exposure (s)   3s U.L.
  White       144-243              98            18.3
  V           250-649             390            18.1
  White       144-979             209            18.6
  V           250-1122            547            18.3
  B           729-738             10             17.1
  U           707-874             39             17.2
  UW1         680-850             39             17.1
  UM2         655-825             39             17.3
  UW2         758-777             20             17.0
  No correction has been made for the high Galactic
reddening of E(B-V)=0.4. We note that this value should
be taken with caution, having the burst occurred at low
Galactic latitude.