GRB 260310A: Long GRB with associated Type Ic-BL supernova at z=0.153

AI Summary

Fermi GBM detected a long gamma-ray burst (T90=86s, Ep=175 keV, Eiso=9.8×10⁵⁰ erg) on 2026-03-10 at 04:57:10 UTC, with optical counterpart AT2026fgk identified at redshift z=0.153. Multi-wavelength follow-up revealed a bright, evolving optical/infrared afterglow with clear supernova features emerging by day 17, classified as Type Ic-BL SN near maximum light. X-ray observations detected a rebrightening episode around day 8-10, with radio detections showing strong emission across cm to mm wavelengths, consistent with a standard GRB afterglow powered by a massive star collapse.

Notices (1)

Fermi GBM — GRB · Tue, 10 Mar 2026 04:57:10 GMT

GCN Circulars (58)

GCN-44462 — GRB 260310A · Mon, 04 May 2026 19:46:05 GMT
The optical counterpart of GRB 260310A was detected 21 days after the trigger in the R filter with a magnitude of about 21.8. The absolute magnitude at the redshift of z=0.153 is not fainter than M_R = -17.5. The afterglow was initially suggested to have a power-law decay with a decay index of -2.1, but this may be affected by the still glowing optical counterpart.

GCN-44375 — GRB 260310A · Tue, 21 Apr 2026 10:40:36 GMT
GRB 260310A underwent a late-time X-ray detection by Chandra, indicating the presence of a persistent emission component.

GCN-44278 — GRB 260310A · Sun, 12 Apr 2026 20:47:14 GMT
GRB 260310A was detected by NuSTAR, revealing the presence of an X-ray afterglow at the location of AT2026fgk. This detection is significant because it provides important insights into the physical properties of the afterglow and the environment in which it is located.

GCN-44248 — GRB 260310A · Thu, 09 Apr 2026 13:57:11 GMT
GRB 260310A/AT2026fgk: Kilonova-Catcher collaboration detected the optical counterpart of a gamma-ray burst at Rc = 20.39, z = 0.153.

GCN-44235 — GRB 260310A · Wed, 08 Apr 2026 02:27:55 GMT
Astronomical alert: GRB 260310A: Continued VLA Multi-frequency Radio Observations

GCN-44234 — GRB 260310A · Tue, 07 Apr 2026 17:22:52 GMT
Astronomical alert: GRB 260310A / AT2026fgk: X-ray rebrightening

GCN-44208 — GRB 260310A · Fri, 03 Apr 2026 13:30:44 GMT
Astronomical alert: GRB 260310A/AT2026fgk: Kilonova-Catcher long term optical monitoring

GCN-44172 — GRB 260310A · Wed, 01 Apr 2026 07:07:05 GMT
Astronomical alert: GRB 260310A / AT2026fgk: Luminance-band optical follow-up with a 28cm telescope in Daocheng

GCN-44160 — GRB 260310A · Mon, 30 Mar 2026 20:08:21 GMT
Astronomical alert: GRB 260310A: VLA Multi-frequency Radio Observations

GCN-44137 — GRB 260310A · Sat, 28 Mar 2026 14:25:31 GMT
Astronomical alert: GRB 260310A: Gemini-North Spectral Confirmation of Supernova Features

GCN-44134 — GRB 260310A · Fri, 27 Mar 2026 23:09:57 GMT
Astronomical alert: SMA Detection of GRB 260310A / AT 2026fgk

GCN-44125 — GRB 260310A · Fri, 27 Mar 2026 08:14:57 GMT
Astronomical alert: GRB 260310A / AT 2026fgk: COLIBRÍ photometric evidence of the emerging supernova

GCN-44124 — GRB 260310A · Fri, 27 Mar 2026 07:39:02 GMT
Astronomical alert: GRB 260310A: OSIRIS+/GTC spectroscopic detection of the associated BL-Ic, SN 2026fgk

GCN-44122 — GRB 260310A · Fri, 27 Mar 2026 00:39:12 GMT
Astronomical alert: GRB 260310A / AT2026fgk: Late-time infrared detection with MIRAGE on the MDM 1.3m telescope

GCN-44119 — GRB 260310A · Thu, 26 Mar 2026 13:15:35 GMT
Astronomical alert: GRB 260310A / AT2026fgk: R- and I-band observations with the PKU 60 cm optical telescope

GCN-44112 — GRB 260310A · Wed, 25 Mar 2026 14:03:49 GMT
Astronomical alert: GRB 260310A/AT2026fgk: Kilonova-Catcher late optical afterglow detection at about 15 days post trigger time

GCN-44104 — GRB 260310A · Tue, 24 Mar 2026 14:51:33 GMT
Astronomical alert: GRB 260310A: LBT optical observations

GCN-44095 — GRB 260310A · Mon, 23 Mar 2026 21:59:34 GMT
A team of astronomers led by Rahul Jayaraman at Cornell University reports the detection of temporal steepening in X-ray data from the Einstein Probe observatory for GRB 260310A, which is associated with the optical transient AT2026fgk. The X-ray decay slope steepened from roughly -0.3 to -1.6 around 8 ± 2 days after the burst. This steepening is contemporaneous with a similar epoch post-burst steepening observed in r-band photometric data from the Palomar P60 telescope.

GCN-44073 — GRB 260310A · Sat, 21 Mar 2026 22:21:34 GMT
Astronomers at IKI, Moscow, and Mondy observatory have continued observing the optical transient AT2026fgk (GRB 260310A), which was initially detected by Fermi/GBM and AstroSat. They obtained new measurements in B and R filters and detected the source in their images. The preliminary photometry shows the transient's magnitudes in B and R filters, and the light curve can be found online.

GCN-44067 — GRB 260310A · Sat, 21 Mar 2026 11:45:32 GMT
A group of astronomers, including those from ABObservatory Rosarno, Università della Calabria, INAF - Osservatorio Astronomico di Palermo, INAF - Osservatorio Astronomico di Brera, Università di Genova, INAF - Osservatorio Astronomico di Capodimonte, Osservatorio 'G. Galilei', Liceo Scientifico Cariati, GAL Hassin, Isnello, Università di Firenze - Osservatorio Polifunzionale del Chianti, INAF - Osservatorio Astronomico di Padova, and the NOCTIS Collaboration, have reported new optical observations of the optical counterpart of GRB 260310A / AT2026FGK. The source was measured at a magnitude of 18.92 +/- 0.10 in the Sloan r band. The photometric calibration was performed using the APASS catalog.

GCN-44065 — GRB 260310A · Sat, 21 Mar 2026 06:49:53 GMT
The KAIT team at UC Berkeley reports the detection of the optical afterglow of GRB 251022A using the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory. The team obtained a set of B, V, R, I, and clear filter images and measured the magnitude in the R band to be 17.98±0.03 at 3.21 days after the gamma-ray burst.

GCN-44063 — GRB 260310A · Sat, 21 Mar 2026 04:50:06 GMT
Astronomical alert: GRB 260310A / AT2026fgk: NuSTAR follow-up detection

GCN-44061 — GRB 260310A · Sat, 21 Mar 2026 01:42:34 GMT
Astronomers using the Three Channel Imager at the Fraunhofer Telescope at Wendelstein Observatory did not observe rebrightening in the optical and near-infrared counterpart of GRB 260310A (AT 2026fgk) as suggested by previous reports. This finding adds to the ongoing investigation of this gamma-ray burst.

GCN-44060 — GRB 260310A · Fri, 20 Mar 2026 22:31:46 GMT
A team of astronomers using the AZT-33IK telescope at Mondy observatory report no evidence of re-brightening in the optical observations of GRB 260310A up to 9.6 days after the initial detection. The team urges follow-up observations to search for a supernova associated with the gamma-ray burst.

GCN-44059 — GRB 260310A · Fri, 20 Mar 2026 20:08:08 GMT
A team of astronomers led by Rosa L. Becerra from UNAM reported the detection of a late rebrightening of AT 2026fgk, a possible counterpart to the Fermi GBM GRB 260310A, using the DDRAGO two-channel wide-field imager on the COLIBRÍ telescope. The rebrightening was observed in all three filters (g, r, z) and had a temporal index of alpha > 1.5.

GCN-44058 — GRB 260310A · Fri, 20 Mar 2026 17:40:46 GMT
Astronomers from Sapienza University of Rome, led by Niccolo’ Passaleva, report the detection of GRB 260310A/AT2026fgk using the Large Binocular Telescope (LBT) and LUCI near-infrared imager, six days after its initial detection by Fermi/GBM and AstroSat CZTI. The team measured a preliminary magnitude of J~18.03 AB mag for the source, consistent with a fading slope of 0.7 compared to previous observations.

GCN-44057 — GRB 260310A · Fri, 20 Mar 2026 14:52:58 GMT
The Northern Extended Millimeter Array (NOEMA) detected radio emission from GRB 260310A, a nearby gamma-ray burst with a redshift of 0.153. Preliminary measurements indicate a flux density of 17 mJy at 100 GHz and a luminosity of 10^42 erg/s. Further observations are planned.

GCN-44053 — GRB 260310A · Fri, 20 Mar 2026 01:38:39 GMT
GRB 260310A, a gamma-ray burst detected by Fermi's GBM, has been classified as a long burst based on its duration (T90 = 86s), peak energy (Ep = 175 keV), and isotropic energy release (Eiso = 9.8e50 erg). Its location on the Ep-Eiso diagram is consistent with long bursts, but its position on the EH-T90 diagram is also within the 2 sigma regions for short bursts. The event was analyzed using publicly available data.

GCN-44045 — GRB 260310A · Wed, 18 Mar 2026 09:14:01 GMT
A radio detection of the gamma-ray burst GRB 260310A / AT 2026fgk was made using the Karl G. Jansky Very Large Array (VLA) three weeks after the initial event. The unresolved radio source was detected at all observed frequencies and its position was consistent with previous X-ray, optical, and infrared observations.

GCN-44044 — GRB 260310A · Wed, 18 Mar 2026 07:47:29 GMT
The Space Variable Objects Monitor (SVOM) team reports on their optical observations of GRB 260310A, a gamma-ray burst detected by Fermi and AstroSat. SVOM used the VT instrument to observe the burst's optical counterpart, AT2026fgk, in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels between March 14-17, 2026. Preliminary measurements reveal magnitudes of 18.44 ± 0.05 mag and 18.94 ± 0.05 mag for VT_R and VT_B, respectively, at 5.26 days, and 18.65 ± 0.05 mag and 19.15 ± 0.05 mag, respectively, at 7.35 days.

GCN-44043 — GRB 260310A · Wed, 18 Mar 2026 06:59:09 GMT
Astronomers at Monash University reported the detection of the optical counterpart AT2026fgk of GRB 260310A using the Las Cumbres Observatory 1m telescope at McDonald Observatory. The observations were carried out approximately 4.05 days after the gamma-ray burst trigger. The team obtained r-band and u-band images, which clearly showed the reported counterpart. The preliminary photometry from the stacked images is 18.58 ± 0.02 mag in r-band and 19.47 ± 0.04 mag in u-band.

GCN-44022 — GRB 260310A · Sun, 15 Mar 2026 17:21:19 GMT
Astronomers at the Aryabhatta Research Institute of Observational Sciences (ARIES) in India used the 1.3m Devasthal Fast Optical Telescope (DFOT) to observe the optical counterpart of GRB 260310A, which was detected by Fermi/GBM and AstroSat. The observation, conducted approximately 4.56 days after the trigger, revealed a clear detection of the counterpart in a single 100s R-band frame, with a magnitude of 18.54 ± 0.12.

GCN-44021 — GRB 260310A · Sun, 15 Mar 2026 16:12:58 GMT
A group of astronomers, including those from ABObservatory Rosarno and NOCTIS team, observed the optical counterpart of GRB 260310A (AT2026fgk) four days after the gamma-ray burst using a 0.30-m telescope. The obtained magnitude was 18.5, confirming the counterpart's continued detection.

GCN-44020 — GRB 260310A · Sun, 15 Mar 2026 15:06:06 GMT
Amateur astronomer Filipp Romanov observed the optical afterglow of GRB 260310A / AT 2026fgk using iTelescope.Net and measured its magnitude to be 18.0 ± 0.1 Rc, six days after the gamma-ray burst. This observation provides valuable data for further analysis.

GCN-44006 — GRB 260310A · Sat, 14 Mar 2026 15:46:52 GMT
SAO RAS team reports optical observations of GRB 260310A counterpart using the Zeiss-1000 1m telescope. The team obtained 300 sec images in B, V, Rc, and Ic filters on March 12/13 and 13/14. The candidate is clearly detected with magnitudes of 18.77, 18.0, 18.92, and 18.14 in the respective filters.

GCN-44005 — GRB 260310A · Sat, 14 Mar 2026 15:23:56 GMT
A team of researchers led by Lauren Rhodes at McGill University, Andrew Hughes and Rob Fender at Oxford University, Joe Bright at Oxford and Breakthrough Listen, and Dave Green and Dave Titterington at Cambridge, reported the detection of radio emission at 15.2 GHz from the position of the gamma-ray burst (GRB) 260310A/AT 2026fgk using the Arcminute Microkelvin Imager Large-Array (AMI-LA) at the Mullard Radio Astronomy Observatory. The team detected an unresolved source with a peak flux density of 9.8 +/- 0.5 mJy/beam, which is significantly higher than the 3sigma upper limit of around 0.5 mJy/beam found in the Very Large Array Sky Survey (VLASS) data. This detection marks the first radio detection of GRB 260310A/AT 2026fgk and provides important insights into the multi-wavelength emission of this cosmic event.

GCN-44004 — GRB 260310A · Sat, 14 Mar 2026 14:48:10 GMT
Astronomers using the Italian 3.6m TNG telescope with the near-infrared camera NICS have detected the optical/NIR counterpart of GRB 260310A, reported by Fermi/GBM and AstroSat CZTI. The counterpart, also known as AT2026fgk, was observed 96.5 hours after the burst and had magnitudes of J = 17.0 ± 0.1 and H = 15.9 ± 0.1 (Vega, calibrated against the 2MASS catalogue).

GCN-44003 — GRB 260310A · Sat, 14 Mar 2026 09:12:46 GMT
Astronomers using the 0.5-m T1 telescope at Osservatorio Astronomico S. Di Giacomo in Italy observed and detected the optical counterpart of GRB 261013A, also known as AT2026fgk, 3.797 days after the gamma-ray burst trigger. The preliminary magnitude measurement is Rc = 18.21 +/- 0.07 mag.

GCN-44002 — GRB 260310A · Sat, 14 Mar 2026 08:19:29 GMT
Astronomers led by Amar Aryan at National Central University reported multiband optical observations of GRB 260310A using the 1m LOT at the Lulin observatory. The optical counterpart, AT2026fgk, was detected in each filter and confirmed by various teams. The presented magnitudes, not corrected for Galactic foreground extinctions, are 18.72±0.02 (g), 18.42±0.02 (r), 18.26±0.02 (i), and 17.96±0.05 (z). The optical counterpart appeared red in multiband photometry.

GCN-44001 — GRB 260310A · Sat, 14 Mar 2026 06:20:02 GMT
A team of international astronomers, led by UNAM, CPPM, IRAP, LAM, and ASU, reported continuing optical observations of AT 2026fgk, a possible counterpart of the Fermi GBM GRB 260310A, using the DDRAGO two-channel wide-field imager on the COLIBRÍ telescope. They detected AT 2026fgk with a preliminary magnitude of r = 18.47 ± 0.01 and estimated a temporal decay index of about -1.2 and a spectral index beta of about -1.1, supporting a synchrotron spectrum and a likely origin in a GRB afterglow.

GCN-44000 — GRB 260310A · Sat, 14 Mar 2026 04:43:17 GMT
A team of researchers led by A. Martin-Carrillo from University College Dublin and CAHA observed the optical counterpart to GRB 260310A using the CAHA 1.23m telescope. They detected the candidate with a preliminary AB magnitude of R = 18.3 and found a shallow decay with a power-law index of ~0.3, shallower than the decay observed earlier. These observations were made as part of undergraduate projects at Calar Alto Observatory.

GCN-43996 — GRB 260310A · Fri, 13 Mar 2026 21:05:01 GMT
A team of astronomers led by Robert Stein from the University of Maryland, College Park, and including researchers from Caltech, Columbia University, Carnegie, CMU, MIT, LAM, and the University of Chicago, used the Palomar 1-m telescope equipped with the WINTER camera to observe the transient AT 2026fgk, identified as the likely counterpart to GRB 260310A. They detected a source in J-band and Hs-band filters, with magnitudes of 17.16 and 16.97, respectively. The observations did not show significant evolution over a ~20 hour baseline, consistent with a power-law decay of an afterglow at this late phase. The team plans further observations.

GCN-43994 — GRB 260310A · Fri, 13 Mar 2026 17:39:34 GMT
The Einstein Probe's Follow-up X-ray Telescope (FXT) detected an uncatalogued X-ray source at the position of GRB 260310A, with a photon index of 1.55 ± 0.09 and an unabsorbed flux of (5.51 ± 0.22) x 10^-12 erg/s/cm^2. This is likely the X-ray afterglow of the gamma-ray burst and encourages further follow-up.

GCN-43993 — GRB 260310A · Fri, 13 Mar 2026 17:35:21 GMT
A team from Sun Yat-sen University observed the afterglow of GRB 260310A using the SYSU 80 cm infrared telescope and detected an infrared counterpart at a magnitude of 16.7 Vega mag, 81 hours after the gamma-ray burst trigger.

GCN-43991 — GRB 260310A · Fri, 13 Mar 2026 14:38:23 GMT
A team of astronomers led by Rosa L. Becerra at UNAM report the detection of the optical counterpart of GRB 260310A using the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional in Mexico. The source, AT2026fgk, was observed on March 10 and 11, with preliminary magnitudes of approximately 16.6 and 17.52, respectively. The team also measured a temporal decay of alpha≈-0.6 between the magnitudes reported by other collaborations. The first night's photometry is tentative due to technical issues.

GCN-43990 — GRB 260310A · Fri, 13 Mar 2026 14:33:29 GMT
A team of astronomers led by M. Pursiainen reported no significant polarization detected for the optical counterpart of GRB 260310A using the Nordic Optical Telescope equipped with ALFOSC. The transient, AT 2026fgk, had an AB magnitude of 18.12 and was observed 2.89 days after the gamma-ray burst trigger. Despite poor seeing conditions, the team secured a sequence of four 900s exposures in linear imaging polarimetry. No correction for Galactic interstellar polarization was applied due to modest extinction.

GCN-43986 — GRB 260310A · Fri, 13 Mar 2026 11:30:56 GMT
A team of astronomers led by Brian Hsu from the University of Arizona observed the possible optical counterpart to GRB 20260310A/AT2026fgk using the B&C spectrograph on the 90-inch Bok telescope. The optical spectrum shows a red continuum with a strong, narrow emission line at 7566 Angstroms, which is attributed to H-alpha from the candidate host galaxy at a redshift of 0.153. This measurement agrees with previous redshift determinations.

GCN-43984 — GRB 260310A · Fri, 13 Mar 2026 11:16:28 GMT
Astronomers using the Gran Telescopio Canarias (GTC) and the OSIRIS+ instrument have confirmed a redshift of z = 0.153 for the optical counterpart AT2026fgk of GRB 260310A. This measurement, which consolidates a previous report, rules out a redshift larger than 0.3 for a long GRB sight line. The transient is located in the outskirts of a galaxy, at a projected distance of ~13.5 kpc from the galaxy core, which is larger than typical for collapsar origins but not unprecedented. The findings suggest that GRB 260310A may have had a merger progenitor.

GCN-43981 — GRB 260310A · Fri, 13 Mar 2026 08:04:42 GMT
A team of astronomers led by Jean-Luc Atteia from IRAP have determined that the gamma-ray burst (GRB) 260310A, which occurred at a redshift of 0.153, lies in the Type I region of the Amati diagram despite being a long GRB. This unusual finding suggests that the burst may be the result of a merger event. To place GRB 260310A in the Type II region of the Amati plot, it would need to be at a higher redshift and not associated with a bright galaxy.

GCN-43980 — GRB 260310A · Fri, 13 Mar 2026 04:01:22 GMT
A group of astronomers led by Enrique Moreno Méndez from UNAM and CPPM observed the possible counterpart of GRB 260310A using the DDRAGO imager on the COLIBRÍ telescope. They detected the source, named AT 2026fgk, with magnitudes of g=18.53, r=18.15, i=17.95, z=17.74, and y=17.63 in the grizY filters. The source is projected to be 11.3 kpc from a nearby galaxy with a photo-z of approximately 0.11 and a likely spectroscopic redshift of 0.153. The association of AT 2026fgk with GRB 260310A is supported by its colors and its low probability of chance alignment with the nearby galaxy.

GCN-43979 — GRB 260310A · Fri, 13 Mar 2026 02:28:03 GMT
A team of researchers led by A. Martin-Carrillo from University College Dublin and the Calar Alto Hamburg ESO Survey (CAHA) observed the optical counterpart of GRB 260310A using the CAHA 1.23m telescope. The candidate was detected in three 150-second exposures in the BVR bands, with a preliminary magnitude of R = 18.2. This observation was made approximately 2.75 days after the Fermi trigger and was part of the final year undergraduate projects at Calar Alto Observatory.

GCN-43978 — GRB 260310A · Fri, 13 Mar 2026 02:18:22 GMT
The MASTER Global Robotic Net detected rebrightening of the optical transient AT2026fgk (MASTER OT J143716.19+715031.2) during 7 hours of observations at the MASTER-Tunka robotic telescope. The transient, discovered by the GOTO system on March 10, 2026, was initially detected with a magnitude of 18.3 in unfiltered images, but later brightened to 17.2. The observations and reduction are continuing.

GCN-43977 — GRB 260310A · Fri, 13 Mar 2026 00:27:51 GMT
Astronomers have identified the optical counterpart of GRB 260310A using spectroscopic observations with the Next Generation Palomar Spectrograph on the Palomar 5.1m Hale Telescope. The redshift of the candidate host galaxy is 0.153, making it one of the closest long-duration gamma-ray bursts to date. The optical spectrum shows a featureless red continuum with a strong, narrow H-alpha emission line at 7566 Angstroms. The gamma-ray fluence and peak observed optical luminosity suggest that this is a low-luminosity long-GRB.

GCN-43975 — GRB 260310A · Thu, 12 Mar 2026 22:19:13 GMT
On March 10, 2026, the Fermi Gamma-ray Burst Monitor (GBM) detected a gamma-ray burst (GRB 260310A) at a redshift of 0.11. The burst, which was also observed by AstroSat, AstroSat-GOTO, and AstroSat-LAST, had a duration of approximately 60 seconds and a peak photon flux of 2.3 ph/s/cm^2 in the 10-1000 keV band. Preliminary spectral analysis revealed a power law function with an exponential high-energy cutoff, with a power law index of -0.15 and a cutoff energy of 172 keV. The event fluence in the 10-1000 keV range was (5.8 +/- 0.4)E-06 erg/cm^2.

GCN-43974 — GRB 260310A · Thu, 12 Mar 2026 19:11:47 GMT
A potential optical counterpart, AT 2026fgk, has been identified for the gamma-ray burst (GRB) 260310A, which was detected by Fermi/GBM and AstroSat. The transient, discovered by GOTO, is highly variable and shows an initial rise and subsequent decay, consistent with previous observations. LAST observations of the field prior to the GRB event time did not detect any transient up to a 5-sigma limiting magnitude of 20.74 (AB). The LAST team encourages further follow-up observations.

GCN-43958 — GRB 260310A · Wed, 11 Mar 2026 07:19:18 GMT
A long gamma-ray burst (GRB 260310A) was detected by the AstroSat CZTI collaboration using data from the CsI anticoincidence (Veto) detector. The burst, also detected by Fermi GBM, occurred in the 100-500 keV energy range and peaked at 2026-03-10 04:57:12.05 UTC. The measured peak count rate was 273 (+67, -57) counts/s above the background, with a total of 2709 (+573, -589) counts. The source was also detected in the 20-200 keV energy range. This detection highlights the capabilities of the AstroSat CZTI collaboration in detecting and analyzing gamma-ray bursts.

GCN-43954 — GRB 260310A · Tue, 10 Mar 2026 16:32:56 GMT
Two MASTER robotic telescopes in Russia, MASTER-Tunka and MASTER-Kislovodsk, observed Fermi GRB 260310A after receiving notice from the Fermi GBM team. The observations began at zenith distances and sun altitudes specific to each telescope location. The upper limits of magnitude detected were 19.9 for MASTER-Tunka and 18.3 for MASTER-Kislovodsk.

GCN-43951 — GRB 260310A · Tue, 10 Mar 2026 05:07:50 GMT
The Fermi Gamma-ray Burst Monitor (GBM) has detected and located a long gamma-ray burst (GRB 260310A) at coordinates RA = 213.6, Dec = 78.7 (J2000) with a statistical uncertainty of 4.3 degrees. The angle from the Fermi Large Area Telescope (LAT) boresight is 124.0 degrees. This significant astronomical event was reported by the Fermi GBM team and data, including the skymap, HEALPix FITS file, and light curve, can be accessed through various URLs.