TITLE: GCN CIRCULAR NUMBER: 38790 SUBJECT: GRB 250101A: NUTTelA-TAO / BSTI Optical Limits DATE: 25/01/03 12:16:34 GMT FROM: Toktarkhan Komesh at Nazarbayev University T. Komesh (NU), Z. Maksut (NU), Z. Abdullayev (NU), B. Grossan (UCB, NU), D. Berdikhan (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) observed the field of GRB 250101A at 14:00:32 UT on 2025-01-02, 24.8 hours after the BAT trigger. Observations were made in clear conditions. No source consistent with the XRT (P.A. Evans et al., GCN 38708; T. Komesh et al., GCN 38777) was detected. We report the following results: t-t0(h) UL g' UL r' exposure_time (s) ----------------------------------------- 24.8 21.0 20.8 300 t is the middle time, t0 is the BAT trigger time, t-t0 is given in hours. UL gives the 5 sigma upper limit sensitivity in magnitudes, for images of the given exposure time. Calibration was done with 4 Pan-STARRS catalog stars on our images. No color or other corrections were applied to the values above. ----------------------------------------------- NU = Nazarbayev University, Astana, 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. AP26103591). 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.