[vsnet-grb-info 2695] GRB 060116: VLT optical observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4532
SUBJECT: GRB 060116: VLT optical observations
DATE:    06/01/17 05:59:55 GMT
FROM:    Daniele Malesani at SISSA-ISAS,Trieste,Italy  <malesani at sissa.it>

P. D'Avanzo (INAF/OABr), D. Malesani, L.A. Antonelli (INAF/OABr), report 
on behalf of the MISTICI collaboration:

We observed the field of GRB 060116 (Campana et al., GCN 4519; Barthelmy 
et al., GCN 4531) with the ESO-VLT UT2 equipped with FORS 1. Observations 
were carried out in the R and I filters, starting on Jan 17.069 UT (17 h 
after the burst).

The object reported by Kocevski, Bloom & McGrath (GCN 4528) is not 
detected in our images down to a limiting magnitude I > 24.5 and R > 24.9 
(3 sigma, calibrated against the USNO-B1 catalog).

Our non detection indicates that the candidate object by Kocevski et al. 
(GCN 4528) is very likely the J-band afterglow of GRB 060116, which faded 
significantly between the two observations.

We further note a faint, red object inside the XRT error box (Campana et 
al., GCN 4522, 4529), at the coordinates (0.3" arcsec error):

   alpha(J2000) = 05:38:46.170;
   delta(J2000) = -05:26:15.08.

This is 2.5" away of the afterglow position (Kocevski et al., GCN 4528).

A finding chart in the I filter is posted at the following URL:
   http://www.merate.mi.astro.it/~davanzo/GRB/grb060116_find_I.jpeg

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