GCN Circular 3616

S. Covino, P. D'Avanzo (INAF, OABr), D. Malesani (SISSA/ISAS), G.L. Israel,
S. Piranomonte (INAF, OARm), G. Tagliaferri (INAF, OABr), G. Chincarini
(Univ Milano-Bicocca), L. Stella (INAF, OARm), report:

Photometric analysis of our set of images of GRB 050714B (Levan et al., GCN 3613
Not found
 
 
;
Tueller et al., GCN 3615
Not found
 
 
) taken with the VLT-FORS1 in the R band
does not confirm the proposed identification of the object reported by Malesani et al.
(GCN 3614
Not found
 
 
) as the candidate optical afterglow.

The object shows constant brightness between Jul 14.984 UT and Jul 15.040 UT
(from 56 to 137 minutes after the GRB, respectively) at about R = 21.7,
taking as reference the USNO star U0675-11455984 with magnitude R = 15.3.
A light curve for this object can be seen at the following URL:

  http://www.sissa.it/~malesani/GRB/050714B/candidate_lc.gif

We give below the refined coordinates for the candidate,
adopting an astrometric solution based on the 2MASS catalog:

   alpha(J2000) = 11:18:47.71,  delta(J2000) = -15:32:51.6

The error is 0.2 arcsec.

We note that two fainter objects are present close to the edge of the XRT error circle

A: alpha(J2000) = 11:18:47.71,  delta(J2000) = -15:33:00.9
B: alpha(J2000) = 11:18:48.19,  delta(J2000) = -15:32:50.3

None of such objects is seen to vary by more than ~0.1 mag.

A finding chart can be found here:

  http://www.sissa.it/~malesani/GRB/050714B/GRB050714B_finder.jpg

This message may be cited.