TITLE:   GCN CIRCULAR
NUMBER:  2725
SUBJECT: GRB040916 optical limits 17 min after GRB
DATE:    04/09/18 08:41:18 GMT
FROM:    Grzegorz Wrochna at Soltan Inst.for Nuclear Studies  <wrochna@fuw.edu.pl>

M.Cwiok, K.Kwiecinska, L.Mankiewicz, K.Nawrocki,
B.Pilecki, L.W.Piotrowski, G.Pojmanski, R.Salanski,
M.Sokolowski, D.Szczygiel, G.Wrochna,
on behalf of "Pi of the Sky / ASAS" collaboration
http://grb.fuw.edu.pl

The central part of HETE FOV containing GRB040916 error box
was observed by "Pi of the Sky" apparatus at Las Campanas
Observatory for the night of 2004.09.15/16
from 00:20:54 UT (17 min after the GRB) till 09:05:00 UT.
10s exposures were taken continuously with 4s intervals
by two CCD cameras.
No unknown objects wrt Tycho-2 and GSC catalogues
has been observed within the GRB040916 error box.
The limiting magnitude is ~11.5m for single frames
and ~13.0m for 20 coadded frames. More information at
http://grb.fuw.edu.pl/pi/ot/grb040916/