TITLE: GCN CIRCULAR NUMBER: 37419 SUBJECT: GRB 240905E: NUTTelA-TAO / BSTI Optical Limits DATE: 24/09/07 05:33:40 GMT FROM: Zhanat Maksut at Nazarbayev University Z. Maksut (NU), B. Grossan (UCB, NU), T. Komesh (NU), Z. 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) observed the field of GRB 240905E, 10 seconds after receipt of an automated GCN / BAT position alert, in Sloan g' and r' bands, with the Burst Simultaneous Three-Channel Imager (Grossan, Kumar & Smoot 2019, JHEA, 32, 14). We started observations of GRB 240905E (Dichiara et al., GCN 37397) at UT 18:26:58 on 2024-09-05, 55 seconds after the BAT trigger. Observations were made in windy conditions. We report the following upper limit results: start time t_m-t0(s) end time UL g' UL r' exposure_time (image x s) ----------------------------------------------------------------------- 18:26:58 57 18:27:03 17.01 17.08 10x0.5 18:39:41 908 18:42:41 18.60 18:61 3x60 20:36:14 7991 20:42:14 19.11 19.15 1x360 The start and end time is in UT. t_m is the middle time, t0 is the BAT trigger time, t_m-t0 is given in seconds. UL gives the 5 sigma upper limit sensitivity in magnitudes, for images co-added to the given exposure time. Calibration was done with 4 Pan-STARRS catalog stars on our images. No color 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. 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, Kazakhstan.