TITLE:   GCN CIRCULAR
NUMBER:  2970
SUBJECT: GRB050123: optical limit 1.8h before GRB
DATE:    05/01/24 09:33:35 GMT
FROM:    Grzegorz Wrochna at Soltan Inst.for Nuclear Studies  <wrochna@fuw.edu.pl>

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

The GRB 050123 (GCN 2966) error box was observed by "Pi of the Sky"
apparatus at Las Campanas Observatory at 8:35 UT, i.e. 1h 48min
before the GRB. 3 exposures, 10s each, have been taken by 2 cameras.
No new object has been found within the HETE error box.
The limiting magnitude on 3 coadded frames is 12m (unfiltered).