TITLE:   GCN CIRCULAR
NUMBER:  37307
SUBJECT: GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
DATE:    24/08/27 04:22:06 GMT
FROM:    Zhanat Maksut at Nazarbayev University <zhanat.maksut@nu.edu.kz>

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 240825A, 3.7 h after receipt 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 of GRB 240825A (Gupta et al., GCN 37274; Jiang et al. GCN 37275; Dutton et al. GCN 37276; Odeh et al. GCN 37277; Zhang et al. GCN 37278; Li et al. GCN 37280; Izzo & Malesani, GCN 37287; Lipunov et al. GCN 37289; Leonini et al. GCN 37291; Wu et al. GCN 37292; Martin-Carrillo et al. GCN 37293) at UT 19:34:01 on 2024-08-25, 3.7 h after the BAT trigger. Observations were made in partly cloudy conditions.  We report the following upper limit results:

start time  t-t0(h)  end time    UL g'   UL r'   exposure_time (s)
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19:34:01     3.7     19:43:01     19.31     19.38    10x60

start time is in UT. t-t0(h) gives the time since the trigger, in hours. 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.
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NU = Nazarbayev University, Nur-Sultan, 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.