{
  "submittedHow": "web",
  "body": "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:\n\nThe Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) pointed at GRB250402A on receipt of an automated GCN / SVOM position alert, observing in Sloan g' and r' bands, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14).\n\nWe started observations at 23:10:30 UT on 2025-04-02, 154 seconds after the SVOM/ECLAIRs trigger (X. Chen et al., GCN 40014). Observations were made in partially cloudy conditions. No source consistent with the SVOM/VT (L. P. Xin et al., GCN 40015) was detected. We report the following results:\n\nstart time  t-t0(s)  end time    UL g'   UL r'  exposure_time (s)\n--------------------------------------------------------------\n23:10:30     154       23:11:30\t 18.01   18.35 \t  60\n23:12:13     257       23:22:13\t 18.58   18.67\t  600\n\nt is the middle time, t0 is the SVOM/ECLAIRs trigger time, t-t0 is given in seconds. 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.\n\n----------------------------------\nNU = Nazarbayev University, Astana, Kazakhstan\nUCB = University of California, Berkeley, USA\nFAI = Fesenkov Astrophysical Institute, Kazakhstan\n\nThis 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.",
  "subject": "GRB 250402A: NUTTelA-TAO Early Optical Limits",
  "submitter": "Toktarkhan Komesh at Nazarbayev University <toktarkhan.komesh@nu.edu.kz>",
  "format": "text/plain",
  "bibcode": "2025GCN.40033....1K",
  "createdOn": 1743706962201,
  "circularId": 40033,
  "eventId": "GRB 250402A"
}