TITLE:   GCN CIRCULAR
NUMBER:  35362
SUBJECT: GRB 231215A: AKO Optical Upper Limit
DATE:    23/12/15 21:33:00 GMT
FROM:    Mohammad Odeh at Al Khatim Observatory M44 <mshodeh@gmail.com>

Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International
Astronomical Center in Abu Dhabi, UAE), and Dalya Akl (American University
of Sharjah, UAE), report:

We used our 0.36m f/7.7 robotic telescope to observe the field of GRB
231215A, which was detected by Swift (D'Avanzo et al., GCN 35343), and its
optical counterpart was detected by (Pankov et al., GCN 35349; Sasada et
al., GCN 35351; An et al., GCN 35353; Wagh et al., GCN 35354).

The observation was done on 15 December starting at 20:07:36 UT, which
corresponds to 10.34 hours after the GRB trigger time, using an (Ic)
filter. We obtained 17x180s images, and we didn't detect a credible source
within the uncertainty radius of the Swift-XRT position (Goad et al., GCN.
35357).

The following 5-sigma upper limit is calculated using the ATLAS catalog as
a reference:
Ic = 18.8
The magnitude is not corrected for Galactic extinction.