TITLE:   GCN CIRCULAR
NUMBER:  19138
SUBJECT: GRB 160303A iTelescope observation
DATE:    16/03/04 02:26:10 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

T. Sakamoto, Y. Kitaoka, A. Yoshida (AGU) 

We observed the field of GRB 160303A detected by Swift (trigger #677495;
Beardmore et al., GCN Circ. 19126) with the iTelescope.Net (http://www.itelescope.net) 
T21 (Plane Wave 17" CDK) telescope located at the New Mexico Skies Observatory 
(NM, USA).  

15 images of 60 sec exposures were taken in the R filter starting from March 3 11:19:26 (UT) 
about 25 minutes after the trigger and stopped on March 3 11:38:20 (UT).  
We do not detect the optical afterglow both in the individual images and the stacked image 
at the X-ray and the optical afterglow position (Evans et al., GCN Circ. 19132; 
Butler et al., GCN Circ. 19131).  The estimated five sigma upper limit of the combined 
image (total exposure of 900 sec) is ~18.3 using the USNO-B1 catalog.