S. Covino, D. Lazzati, G. Ghisellini, P. Saracco, S. Campana, G. Chincarini
(Observ. of Brera, Milan, Italy); S. Di Serego, A. Cimatti (Observ. of
Arcetri, Florence, Italy); L. Vanzi, L. Pasquini (ESO, Garching, Munich,
Germany); F. Haardt (Univ. of Insubria, Como, Italy); M. Vietri (Univ. of
Rome III, Italy); L. Stella (Observ. of Monte Porzio, Rome, Italy);
R. Falomo (Observ. of Padua, Italy); H. Boehnhardt, F. Bresolin, P. Moller,
G. Rupprecht (ESO-VLT service team), report:
We made imaging polarimetry of the optical transient associated to
GRB 990510 at ESO-VLT-FORS1 on 1999 May 11.13509, in the R band, when
the R-magnitude of the object was 19.1+/-0.02.
We found linear polarization at the level of 1.7+/-0.2 per cent with
position angle 12+/-4 degrees, relative to the stars in the field.
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