Fermi GBM Triggers 250702B, C, D and E are likely from the same source

ATel #17259; E. Neights (GWU, NASA GSFC), O. J. Roberts (USRA, NASA MSFC), E. Burns (LSU), P. Veres (UAH) report on behalf of the Fermi-GBM Team:
on 2 Jul 2025; 19:48 UT
Credential Certification: Oliver Roberts (oliver.roberts@nasa.gov)

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At 13:09:02.03 UT, Fermi GBM triggered on GRB 250702D and was initially localized to an RA and Dec of 292.9 and 3.6 (19h, 31m, +03,33'; J2000), with an error of 14.7 deg. The light curve shows several peaks occurring over ~60 seconds.

Since then, an additional three bursts have triggered GBM with similar lightcurve characteristics and localizations. The trigger times and localizations are summarized as follows:

GRB Name    MET (s)         Time (UT)       RA (deg)    Dec (deg)    Err (deg)
250702E        773166098    16:21:33.07    286.8         -17.7           11.6       (GCN 40890)
250702C        773160576    14:49:31.91    270.3         1.4              12.7       (GCN 40885)
250702B        773157370    13:56:05.77    286.0         -8.7              7.8        (GCN 40886)
250702D        773154547    13:09:02.03    292.9         3.6              14.7       (GCN 40883)

Despite the similar position lying close to or on the galactic plane, we observe photons in the BGO up to 1 MeV, with the majority of the photons occurring in the 50-300 keV range, which suggest the source may not be a typical galactic source and might be an ultra-long GRB or another source class. If a GRB origin is confirmed, it is 11.5 ks long, making it one of the longest ultra-long GRBs detected.

The combined GBM skymap can be found here: https://zenodo.org/records/15793558. The skymaps are all associated with each other with confidence between 89.2 and 98.5%.

There were no joint-GW detections during these triggered times.

We strongly suggest follow-up of the region to determine the nature of the source over multiple wavelengths.