GCN Circular 2803

S. Covino, D. Malesani, G. Tagliaferri, P. D'Avanzo, L.A. Antonelli,
G. Chincarini, M. Della Valle, F. Fiore, D. Fugazza, L. Stella,
on behalf of the MISTICI collaboration, report:

We observed the optical afterglow (Da Costa, Noel & Price, GCN 2765
Not found
 
 
;
Maeno et al. GCN 2772
Not found
 
 
) of GRB 041006 (Galassi et al., GCN 2770
Not found
 
 
)
with the 8.2m ESO-VLT-UT2 (Kueyen) at Cerro Paranal. Observations
were carried out under good observing conditions (seeing 0.9")
with the FORS1 instrument.

The afterglow is clearly detected in the B, R and I bands. We report
the following magnitude for the object (calculate performing PSF photometry):

  R = 23.59 +- 0.06 on 2004 Oct 11.121 UT

The decay seem therefore even steeper than that inferred from the previous
TNG observations (Fugazza et al., GCN 2782
Not found
 
 
; D'Avanzo et al., GCN 2788
Not found
 
 
).

In our coadded images, we also detect an extended emission surrounding
the afterglow, apparently 2.5" in size (18 kpc at z=0.712; Fugazza et al.,
GCN 2782
Not found
 
 
; Price et al., GCN 2791
Not found
 
 
). As suggested by Fynbo et al. (GCN 2802
Not found
 
 
),
this is likely the host galaxy of GRB 041006. Performing PSF photometry,
we estimate that the contribution inside the afterglow PSF area is
likely very small. The afterglow is located inside the galaxy,
about 1" South East of its nucleus.

A snapshot centered about the GRB position is posted online at the following URL:

http://www.sissa.it/~malesani/GRB/041006

together with an updated light curve with all public data.

We acknowledge the excellent support from the observing staff at Paranal.


This message may be cited.

[GCN OPS NOTE (18:00 14oct04 UT)  As per author's request, the line:
"The afterglow is located inside the galaxy, about 1" South West of its nucleus."
was changed to:
"The afterglow is located inside the galaxy, about 1" South East of its nucleus."
Line_breaks were also added.]