GCN Circular 42922
Subject
EP251130a: Mondy optical observations
Event
Date
2025-12-01T15:00:28Z (2 days ago)
From
Alina Volnova at IKI RAS <alinusss@gmail.com>
Via
Web form
A. A. Volnova (IKI), A. S. Pozanenko (IKI), E. Klunko (ISTP), N. S. Pankov (HSE, IKI) report on behalf of IKI-GRB-FuN:
We observed the field of the X-ray transient EP251130a (Wu et al., GCN 42903; Zhang et al., GCN 42915), also detected by Swift/XRT (Evans et al., GCN 42908) with the AZT-33IK 1.5m telescope of the Sayan Solar Observatory (Mondy) starting on 2025-11-30 (UT) 15:06:18 in R filter. The optical counterpart (Dornic et al., GCN 42904; He et al. GCN 42914; Gupta et al. GCN 42916; Zheng et al. GCN 42917; van Dalen et al., GCN 42918; Moskvitin and Spiridonova, GCN 42919; Aryan et al., GCN 42921) is detected in the stacked frame. Preliminary photometry is the following:
Date UT start t-T0 Exp. Filter OT Err. UL Site/Instrum
(mid,days) (n*s) (3sigma)
2025-11-30 15:06:18 0.18716 60*120 R 21.76 0.20 22.1 Mondy/AZT-33IK
The photometry is calibrated using USNO-B1.0 stars from Moskvitin and Spiridonova, GCN 42919, and is not corrected for the Galactic extinction.