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GCN Circular 42713

Subject
The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
Date
2025-11-17T09:56:34Z (5 days ago)
From
Alina Volnova at IKI RAS <alinusss@gmail.com>
Via
Web form
A. Volnova (IKI), E. Klunko (ISTP), A. Pozanenko (IKI) report on behalf of IKI-GRB-FuN:

We observed the field of the EP-WXT trigger 01709247588 (Feng et al., GCN 42510) with the AZT-33IK 1.5m telescope of the Sayan Solar Observatory (Mondy) in the R-filter starting Oct., 29, 2025, UT 16:48:48, and taking several frames with 120 s exposures. The Emission-line Star PM J04472+2038 likely associated with the transient is clearly detected and not saturated. Preliminary photometry and observational details are the following:

Date        UT start  MJD          Exp.    Filter  Star   Err.  UL       
                     (mid)        (n*s)                        (3sigma)  
2025-10-29  16:48:48  60977.71098  15*120  R       13.25  0.08  22.2

The photometry is based on several nearby USNO-B1.0 stars (R2-magnitudes) and is not corrected for the Galactic extinction, all magnitudes are in Vega system. The star PM J04472+2038 is at least 0.4 mag brighter in our observations comparing to USNO-B1.0 and UCAC catalogues: UCAC R = 13.99 +/- 0.09, USNO-B1.0 R1 = 13.65, R2 = 14.07. This 0.4m brightness increase 5.5 hours after the EP-WXT trigger may confirm the connection between EP-WXT 01709247588 and the stellar flare.
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