TITLE: GCN CIRCULAR NUMBER: 38710 SUBJECT: GRB 241229B: NUTTelA-TAO / BSTI Optical Limits DATE: 24/12/29 16:53:38 GMT FROM: Toktarkhan Komesh at Nazarbayev University <toktarkhan.komesh@nu.edu.kz> T. Komesh (NU), Z. Abdullayev (NU), Z. Maksut (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) pointed at GRB 241229B on receipt of an automated GCN / BAT position alert, observing in Sloan g' and r' bands, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14). We started observations at 01:37:16 UT on 2024-12-29, 61 s after the BAT trigger. Observations were made in partly cloudy conditions. No source consistent with the XRT (P.A. Evans et al., GCN Circ. 38708) was detected. We report the following results: start time t-t0(s) end time UL g' UL r' exposure_time (s) -------------------------------------------------------------- 01:37:16 61 1:37:41 - 16.67 25 01:38:25 135 1:40:25 16.21 17.35 120 The start and end time is in UT. t is the middle time, t0 is the BAT trigger time, t-t0 is given in seconds. UL gives the 5 sigma upper limit sensitivity in magnitudes, for images co-added to the given exposure time. The first row in the table corresponds to co-adds of an initial short exposure image sequence of 1 s (these sub-second exposures are read-noise suppressed by our EMCCD cameras, with high gain electron multiplication active; other images are taken in conventional CCD operation mode) for r'. The second row corresponds to co-adds from a continuing series of 15 s exposures for g' and r’. Calibration was done with 3 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. 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/38710. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...