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GCN Circular 36692

EP240617a is likely a GRB event
2024-06-18T15:51:31Z (a month ago)
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Jun Yang (NJU), Yi-Han Iris Yin (NJU), Binbin Zhang (NJU), Hui Sun (NAOC), Qinyu Wu (NAOC) and Xuefeng Wu (PMO) report on behalf of large collaboration:

Our team has followed up on EP's X-ray flare detection at 2024-06-17T12:19:13 UTC (EP240617a; GCN Circular 36691) and discovered a weak, untriggered gamma-ray transient in the Fermi/GBM data within the occurrence time interval of EP240617a. This transient lasted approximately 100 seconds and its location aligns with that of EP240617a.

Considering the factors that the gamma-ray transient is consistent with EP240617a in terms of event time and location, we are inclined to claim that this is likely a GRB event. A preliminary spectral analysis indicates that its peak energy is below one hundred keV, which suggests its classification as an X-ray rich GRB.

We strongly recommend further follow-up on EP240617a to confirm its physical nature and to detect any afterglows.
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