TITLE: GCN CIRCULAR NUMBER: 39419 SUBJECT: GRB 250219A: NUTTelA-TAO / BSTI Optical Limits DATE: 25/02/22 07:47:55 GMT FROM: Toktarkhan Komesh at Nazarbayev University <toktarkhan.komesh@nu.edu.kz> T. Komesh (NU), Z. Abdullayev (NU), Z. Maksut (NU), D. Berdikhan (NU), B. Grossan (UCB, NU), M. Krugov (FAI) and E. Abdikamalov (NU) report on behalf of the Energetic Cosmos Laboratory: We imaged the field of GRB 250219A with the Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) starting at 21:54:17 UT on 2025-02-19, 6.0 hours after the SVOM/ECLAIRs trigger (F. Daigne et al., GCN 39376). Observations were made in clear conditions. No source consistent with the XRT (J. A. Kennea et al., GCN 39379) was detected. We report the following results: start time t-t0 (minute) end time UL g' UL r' exposure_time (s) ------------ -------------------------------------------------- 21:54:17 361 21:55:17 19.29 19.09 60 21:58:38 365 22:02:38 19.57 19.49 240 t is the middle time, t0 is the SVOM/ECLAIRs trigger time, t-t0 is given in minutes. 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/39419. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...