TITLE: GCN CIRCULAR NUMBER: 35004 SUBJECT: GRB 231111A NUTTelA-TAO / BSTI Early Measurements DATE: 23/11/12 18:00:28 GMT FROM: Toktarkhan Komesh at Nazarbayev University T. Komesh (NU), B. Grossan (UCB, NU), Zh. Maksut (NU), Zh. Abdullayev (NU), M. Krugov (FAI), and E. Abdikamalov (NU) report on behalf of the Energetic Cosmos Laboratory: The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) pointed at GRB231111A on receipt of an automated GCN / BAT position alert, observing in Sloan g', r' and i' bands, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14). We started observations at UT 2023-11-11 14:18:02, 43 s after the BAT trigger. Observations were made under partially cloudy conditions. A new and changing source consistent with the XRT position (Osborne 2023, GCN 34991) was detected. Note that these observations provide essentially full-time coverage, simultaneous in all three bands. We report the following photometric values for the OT: tc-t0(s) g'(mag) r'(mag) i'(mag) exposure_time (s) ---- ----- ----- ----- ----- 69 16.6 16.3 16.0 52.5 133 16.8 16.3 16.4 75 208 17.1 16.7 16.7 75 283 17.2 16.8 16.8 75 358 17.3 16.9 16.8 75 433 17.5 17.2 17.0 75 508 17.6 17.3 17.2 75 583 17.6 17.4 17.3 75 658 17.7 17.5 17.3 75 733 18.0 17.7 17.3 75 808 17.9 17.7 17.6 75 883 18.1 17.9 17.6 75 958 18.0 17.8 17.7 75 1033 18.0 17.9 17.6 75 1108 18.2 18.0 17.6 75 1183 18.0 18.2 17.9 75 1296 18.4 18.3 18.0 150 1446 18.4 18.2 17.9 150 Uncertainties are estimated at ~ 0.1 mag for all three filters. tc-t0 = trigger time minus image center time. Calibration was done with 5 bright Pan-STARRS catalog stars on our images, and no other analysis or corrections. We caution the reader that these are preliminary results, without color or other corrections, and will likely change in small measure. Please also note that times are approximate. ---------------------------------- NU = Nazarbayev University, Nur-Sultan, Kazakhstan UCB = University of California, Berkeley, USA FAI = Fesenkov Astrophysical Institute, Kazakhstan This research has been funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP14870504). The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.