[vsnet-grb-info 3770] GRB 060923C: VLT J-band observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5604
SUBJECT: GRB 060923C: VLT J-band observations
DATE:    06/09/24 18:11:53 GMT
FROM:    Daniele Malesani at SISSA-ISAS,Trieste,Italy  <malesani at sissa.it>

Stefano Covino (INAF/OABr), Daniele Malesani (SISSA/ISAS), and Gianpiero 
Tagliaferri (INAF/OABr), report on behalf of the MISTICI collaboration:

We imaged the field of GRB 060923C (Stamatikos et al., GCN 5591) on 2006 
Sep 24 from 3:39 to 4:16 UT with the ESO VLT+ISAAC in the J band under 
good seeing conditions.

Within the refined XRT error circle (Perri et al., GCN 5601) we detect 
three sources with the following positions (RA, DEC, J2000) and magnitudes:

    A:    23:04:28.40, +03:55:29.1    19.23 +- 0.03
    B:    23:04:28.31, +03:55:29.0    22.87 +- 0.12
    C:    23:04:28.18, +03:55:28.5    21.33 +- 0.07

Source C could be extended. Absolute magnitudes are calibrated with 
respect to two 2MASS stars in the field. The reported errors are only 
statistical; the absolute calibration error may be of the order of ~0.15 
mag. At this stage, we cannot say whether any of these sources is 
related to GRB 060923C. A finding chart is posted at the followin URL:

http://www.sissa.it/~malesani/GRB/060923C/finder_ISAAC.jpg

Source A has been reported by Rau et al. (GCN 5598) and could also be 
marginally visible in the DSS.

We acknowledge support from the ESO observing staff at Paranal, in 
particular Christophe Dumas and Emmanuel Jehin.

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