TITLE:   GCN CIRCULAR
NUMBER:  44904
SUBJECT: EP260610b: MAO/AZT-22 optical observations
DATE:    26/06/11 04:37:49 GMT
FROM:    Yodgor Rajabov at UBAI <rajabov@astrin.uz>

O. Burkhonov, Y. Rajabov, B.Abidkhanov, S. Ehgamberdiev, Y. Tillayev, T. Boyqobilov, A. Shaymanov report on behalf of UBAI team.

We observed the field of EP transient EP260610b (Wu et al., GCN 44895), with the AZT-22 1.5m telescope of the Maidanak Observatory (MAO) starting on 2026-06-10 at 20:09:52 UT. In total we obtained 6x300 s exposures in the R-band using 4kx4k CCD SNUCAM camera (Im et al., 2010). 
The optical counterpart (Levan et al., GCN 44897; Xin et al., GCN 44900; Zhu et al., GCN 44902) is detected in the stacked frame. 

Preliminary photometry is the following:
Date       MidTime  Exptime     t-T0         Filter OT    Err.    UL    SNR   Site/Telescope
                    (nxs)     (mid, days)                 
2026-06-10T20:24:52  6x300      0,317072       R   22.85   0.15    23.26  6.4  MAO/AZT-22

All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022) web interface called STDweb (Karpov et al., 2025).
Images obtained in Johnson Cousins filters were calibrated using the Gaia DR3 Synphot catalog.
The data has not corrected for the Galactic extinction.

Maidanak astronomical observatory (MAO) is an observational facility of the Ulugh Beg Astronomical 
Institute (UBAI), Uzbekistan Academy of Sciences (http://maidanak.uz/).