GCN Circular 45643
Subject
EP260806a: Yamaguchi Interferometer radio detections
Event
Date
2026-09-19T10:11:52Z (a day ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
Via
Web form
Shogo Nohara, Natsuki Maekawa, Hiroki Takebuchi, Kotaro Niinuma, Kenta Fujisawa (Yamaguchi University)
Takanori Sakamoto (Aoyama Gakuin University)
We observed the Einstein Probe transient EP260806a (Li et al., GCN 45299) with the Yamaguchi Interferometer (Fujisawa et al., 2022) in Yamaguchi, Japan, on August 18, September 11, and September 16, 2026 UTC. The observations were conducted simultaneously at central frequencies of 6856 and 8448 MHz, with a bandwidth of 512 MHz for each frequency band. We used 3C48 and J0043+3426 as the flux and gain calibrators. We summarize our measurements of EP260806a at each observing epoch in the table below. The upper limits are quoted at the 3-sigma noise level.
MJD 6856 MHz flux [mJy] 8448 MHz flux [mJy]
61270.57 < 1.77 < 2.57
61294.85 Affected by RFI 7.03+/-0.86
61299.52 8.02+/-0.46 9.26+/-0.77
Our observations are consistent with the radio emission reported at 10 GHz with the VLA (Ho et al., GCN 45547). The measurements performed on September 16 suggest a flat or inverted radio spectrum between 6856 and 8448 MHz.
We will continue monitoring the radio flux of EP260806a with the Yamaguchi Interferometer.