TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3432
SUBJECT: GRB 050520: OSN optical observations
DATE:    05/05/20 01:50:54 GMT
FROM:    Alberto Castro-Tirado at LAEFF-INTA  <ajct@laeff.esa.es>

A. de Ugarte Postigo, A. J. Castro-Tirado, A. Sota,
M. Jelínek, J. Gorosabel and S. Guziy (IAA-CSIC Granada) 

report:

"Following the detection by INTEGRAL of GRB 050520 
(Gotz et al. GCN Circ. 3430), we have taken images 
in the VRI bands with the 1.5m telescope at IAA's  
Observatorio de Sierra Nevada, starting at 00:39 UT
(i.e. 30 minutes after the event).  The co-add of 
the first three I-band frames (3 x 300 s exposure 
time) reveals no optical counterpart in the 1.5' 
radius error box down to the DSS2 limiting magnitude. 
Further analysis is ongoing."

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