[vsnet-grb-info 7126] GRB081222 optical limit by Pi of the Sky

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8707
SUBJECT: GRB081222 optical limit by "Pi of the Sky"
DATE:    08/12/22 16:23:11 GMT
FROM:    Marcin Sokolowski at Soltan Inst. Nuc Studies,Warsaw  <msok at fuw.edu.pl>

M.Cwiok, W.Dominik, G.Kasprowicz, A.Majcher, A.Majczyna,
K.Malek, L.Mankiewicz, K.Nawrocki, L.W.Piotrowski,
D.Rybka, M.Sokolowski, J.Uzycki, G.Wrochna, M.Zaremba, A.F.Zarnecki
on behalf of "Pi of the Sky" collaboration http://grb.fuw.edu.pl

During the night 20081222 the "Pi of the Sky" apparatus observed the
position of GRB081222 in the sky scan mode.
Three 10s images of this field have been taken at 02:10:44 - 02:11:21
( 2 hours 43 min 16 sec before the GRB).
No new object is seen within the error box and the limit is 12.5 
magnitudo.

After receiving the trigger from Swift, the field was observed 63s after
the GRB. No new object has been found within the Swift-BAT error box.
The limiting magnitude (unfiltered) on single 10s exposures is:

         04:55:03 - 04:55:13 - 12.0 mag
         04:55:16 - 04:55:26 - 12.0 mag
         04:55:28 - 04:55:38 - 12.0 mag

The field was observed until 06:00:17, no new object brighter then 12.0mag
was observed. The limit on 20 coadded images is 12.5 mag.