TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3930
SUBJECT: GRB 050904: more VLT NIR observations
DATE:    05/09/06 18:28:44 GMT
FROM:    Gianpiero Tagliaferri at OAB-INAF  <taglia@merate.mi.astro.it>

P. D'Avanzo (INAF/OABr), L.A. Antonelli(INAF/OAR), S. Covino 
(INAF/OABr), A. Grazian, V. Testa (INAF/OAR), D. Malesani (SISSA), D. 
Fugazza, G. Tagliaferri (INAF/OABr), G. Chincarini (INAF/OAB & UNIMIB), 
L. Stella (INAF/OAR), and A. Fernandez-Soto (Univ. Valencia) report on 
behalf of the MISTICI collaboration:

We continued monitoring the afterglow (Haislip et al., GCN 3913; 
D'Avanzo et al., GCN 3921) of GRB 050904 (Cummings et al., GCN 3910; 
Mineo et al., GCN 3920) with the ESO VLT-UT1 (equipped with ISAAC). 
Observations were performed in the J, H, and K bands, at about 50, 51 
and 51.5 hours after the burst.

We still detect the afterglow in all filters. The measured magnitudes 
are consistent with an unbroken decay with slope ~1 from 3 to ~50 hr 
after the GRB.

We thank the ESO staff, in particular Nancy Ageorges for carefully 
performing our observations and quickly providing the data.

More observations are planned.

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