TITLE:   GCN CIRCULAR
NUMBER:  9426
SUBJECT: GRB090518B optical limit by "Pi of the Sky"
DATE:    09/05/27 13:54:07 GMT
FROM:    Marcin Sokolowski at Soltan Inst. Nuc Studies,Warsaw  <msok@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

The "Pi of the Sky" apparatus observed error box of Fermi GRB090518B
before, during and after the burst, starting 23 minutes before the
Fermi trigger. No new source brighter than 11 mag has been identified
on 10s exposures.