TITLE:   GCN CIRCULAR
NUMBER:  43476
SUBJECT: EP260119A: Mondy I-Band Observations
DATE:    26/01/20 18:05:21 GMT
FROM:    Nicolai Pankov at IKI <colinsergesen@gmail.com>

N. Pankov (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), A. Volnova (IKI) report on behalf of IKI-GRB-FuN:

We observed the field of the EP260119a (Jiang et al., GCN 43447; Cheng et al., GCN 43449) at the redshift of z ~ 5.47 (Corcoran et al., GCN 43469) with the AZT-33IK 1.5-meter telescope of the Mondy observatory. We obtained 45x120 sec total exposure in the I-band, starting on 2026-01-19 at 17:18:42 UT.

The afterglow (Fortin et al., GCN 43450; GCN 43455; Eyles-Ferris et al., GCN 43452; Moskvitin & Spiridonova, GCN 43463; Liu et al., GCN 43464; Ma et al., GCN 43466; Zheng et al., GCN 43468; Corcoran et al., GCN 43469; Bochenek & Perley, GCN 43472) is clearly detected in the stacked image. The preliminary photometry and observation details are provided below:

Date        UT start  t-T0       Exp.    Filter Mag    MagErr.   UL
                     (mid,days)  (n*s)                         (3sigma)
2026-01-19  17:18:42  0.74299    45*120  I      20.87  0.11     22.2

The photometry is based on the same stars used by (Moskvitin & Spiridonova, GCN 43463) and has not been corrected for the Galactic extinction.