TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  321
SUBJECT: GRB990510: optical observation
DATE:    99/05/12 15:43:02 GMT
FROM:    Gabriele Ghisellini at Obs.Astro. di Brera  <gabriele@merate.mi.astro.it>

S. Covino, D. Fugazza, G. Ghisellini, D. Lazzati, of the Observatory
of Brera (Milan, Italy) report:

We have obtained R=18.96+-0.02 for the OT of GRB990510,
observed with 3x10 second exposures of VLT-FORS1 at May 11.0468.
This estimate is based on the USNO star at RA = 13:38:00.82, 
DEC=-80:29:11.7, for which we have assumed R = 16.5.
The faint object 2" south of the OT is also visible, with 
approximately R=21.9+-0.2 (see GCN 314).

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