[vsnet-grb-info 2724] GRB 060121: candidate optical counterpart

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4561
SUBJECT: GRB 060121: candidate optical counterpart
DATE:    06/01/22 12:55:46 GMT
FROM:    Daniele Malesani at SISSA-ISAS,Trieste,Italy  <malesani at sissa.it>

D. Malesani (SISSA/ISAS), L.A. Antonelli (INAF/OAR), S. Covino 
(INAF/OABr), E. Palazzi (INAF/IASF Bo), G. Andreuzzi (INAF/TNG), and G. 
Tessicini (INAF/TNG), report on behalf of a larger Italian collaboration:

We observed the field of GRB 060121 (Arimoto et al., GCN 4550;  
Prigozhin et al., GCN 4551; Boer et al., GCN 4552) at two epochs with 
the Italian TNG telescope located in the Canary Islands. Photometry was 
performed in the R-band starting on Jan 22.021 UT (Antonelli et al., GCN 
4556) and Jan 22.193 UT (2.1 and 6.2 h after the GRB, respectively). The 
second run provided images of lower quality, due to bad observing 
conditions.

Inside the XRT error circle (Mangano et al., GCN 4560), we see a faint 
source which is detected in our first dataset but is not detected in the 
second epoch (which is, however, shallower).

The coordinates are (J2000):
 alpha = 09:09:51.93
 delta = +45:39:45.4
We estimate an error of about 0.5" (mainly due the low S/N of the object).

Even if at the moment we do not makeany claim of variability, we suggest 
this object may be the optical counterpart of GRB 060121.

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