GCN Circular 15593

D. Kawamura, T. Sakamoto, I. Takahashi, S. Sugai, A. Yoshida (AGU)

We observed the field of INTEGRAL Weak trigger #6403 with the 12-inch 
AGU Robotic Optical Monitor for Astrophysical object - Narrow (AROMA-N) 
located at the Sagamihara campus of Aoyama Gakuin University.  

60 images of 10 sec exposures and 30 images of 60 sec exposures were 
taken in the R filter starting from December 13 10:45:22 (UT) about 109 sec 
after the trigger (103 sec after the INTEGRAL weak trigger notice) and 
stopped on December 13 11:40:24 (UT).  We do not detect the optical 
afterglow both in the individual images and the stacked image, which 
combined 89 good quality images, inside the INTEGRAL weak position.  
The estimated five sigma upper limit of the combined image (total exposure 
of  2390 sec) is ~17.0 mag using the USNO-B1 catalog.