GRB 260714B — All Circulars

V. Panteleeva, D. Frederiks, A. Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 260714B
(Fermi-GBM detection: The Fermi GBM team, GCN 45161;
Fermi-LAT detection: Gupta and  Lalla, GCN 45162;
AstroSat-CZTI detection: Pathak et al., GCN 45163;
GECAM-B detection: Ren et al., GCN 45174;
SVOM-GRM detection: Ren et al., GCN 45176;
Insight-HXMT-HE detection: Luo et al., GCN 45188) 
triggered Konus-Wind at T0=66206.858 s UT (18:23:26.858).

The burst light curve shows a multipeaked structure
which starts at ~T0-0.4 s and has a total duration of ~15.5 s.
The emission is seen up to 2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB260714_T66206/

As observed by Konus-Wind, the burst
had the total fluence of 3.09(-0.20,+0.23)x10^-5 erg/cm2,
and the 64-ms peak flux, measured from T0+2.640 s,
of 1.39(-0.15,+0.16)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+15.360 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.07(-0.04,+0.04),
the high energy photon index beta = -3.61(-6.39,+0.71),
the peak energy Ep = 595(-44,+55) keV
(chi2 = 122/94 dof).

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+7.168 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.94(-0.05,+0.05),
the high energy photon index beta = -2.97(-1.36,+0.38),
the peak energy Ep = 605(-51,+56) keV
(chi2 = 66/79 dof).

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.

V. Panteleeva, D. Frederiks, A. Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 260714B
(Fermi-GBM detection: The Fermi GBM team, GCN 45161;
Fermi-LAT detection: Gupta and  Lalla, GCN 45162;
AstroSat-CZTI detection: Pathak et al., GCN 45163;
GECAM-B detection: Ren et al., GCN 45174;
SVOM-GRM detection: Ren et al., GCN 45176;
Insight-HXMT-HE detection: Luo et al., GCN 45188) 
triggered Konus-Wind at T0=66206.858 s UT (18:23:26.858).

The burst light curve shows a multipeaked structure
which starts at ~T0-0.4 s and has a total duration of ~15.5 s.
The emission is seen up to 2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB260714_T66206/

As observed by Konus-Wind, the burst
had the total fluence of 3.09(-0.20,+0.23)x10^-5 erg/cm2,
and the 64-ms peak flux, measured from T0+2.640 s,
of 1.39(-0.15,+0.16)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+15.360 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.07(-0.04,+0.04),
the high energy photon index beta = -3.61(-6.39,+0.71),
the peak energy Ep = 595(-44,+55) keV
(chi2 = 122/94 dof).

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+7.168 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.94(-0.05,+0.05),
the high energy photon index beta = -2.97(-1.36,+0.38),
the peak energy Ep = 605(-51,+56) keV
(chi2 = 66/79 dof).

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.

Xing-Hao Luo, Chen-Wei Wang, Chao Zheng, and Shao-Lin Xiong (IHEP) report on behalf of the Insight-HXMT team:

At 2026-07-14T18:23:29.500 (T0), Insight-HXMT/HE detected the GRB 260714B, which is also detected by Fermi/GBM (Fermi GBM Team, GCN #45158) AstroSat CZTI (U. Pathak et.al., GCN#45163), GECAM-B (Yang-Zhao Ren et.al., #45174) and SVOM/GRM (Yang-Zhao Ren et.al., GCN#45176).
	
The Insight-HXMT/HE light curve mainly consists of multiple pulses with a T90 of 10.88 +0.02/-0.04 s. The 1s peak rate, measured from T0+0.13 s, is 8893 cnts/sec. Insight-HXMT/HE detected a total of 36543 counts from this burst.

The HXMT/HE light curve can be found here:
https://www.bursthub.cn/gcn/2026/hxmtgrb260714B.png

All measurements above are made with the CsI detectors of Insight-HXMT/HE operating in the regular mode with the energy range of about 60-900 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://hxmten.ihep.ac.cn/

SVOM/GRM team: Yang-Zhao Ren, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)

SVOM/ECLAIRs team: Olivier Godet (IRAP)
Report on behalf of the SVOM team:

SVOM/GRM was triggered in-flight by GRB 260714B at 2026-07-14T18:23:29.900 UTC (T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45161), Fermi/LAT (Gupta et. Al., GCN #45162), AstroSat/CZTI (Pathak et. al., GCN #45163) and GECAM-B (Ren et. al., GCN #45174).

With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multiple pulses with a T90 of 24.0 +4.5/-5.5 s in the 15-5000 keV band.

The SVOM/GRM light curve can be found here:
https://www.bursthub.cn/gcn/2026/svgrb260714B.png

In addition, the position of this burst, as determined by Fermi/GBM (RA= 166.4, Dec=46.7, ERR= 4 degrees, GCN #45161), is located at about 149 degrees from the SVOM optical axis, which is outside the ECLAIRs field of view. And ECLAIRs was not collecting data at the time of the burst.

With this localization, the time-averaged spectrum from T0-2 to T0+14 s is best fitted by a power law function with an exponential high-energy cutoff. The power law index is -1.13 +0.15/-0.16 and the cutoff energy, parameterized as Epeak, is 616 +119/-87 keV. The event fluence (10-1000 keV) in this time interval is (3.39 +0.12/-0.11)E-05 erg/cm^2.

The 1s peak spectrum, measured from T0-0.4 to T0+0.6 s, if fitted by a power law function with an exponential high-energy cutoff, the power law index is -0.81 +0.17/-0.19 and the cutoff energy, parameterized as Epeak, is 955 +173/-133 keV. The flux (10-1000 keV) in this time interval is (2.12 +0.07/-0.07)E-06 erg/cm^2/s.

The localization of GRB 260714B in the 'Amati' relation diagram is shown at: 
https://www.bursthub.cn/gcn/2026/svgrb260714B_amati.png
The localization of GRB 260714B in the 'Yonetoku' relation diagram is shown at: 
https://www.bursthub.cn/gcn/2026/svgrb260714B_yonetoku.png 

The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS.

The SVOM point of contact for this burst is: Yang-Zhao Ren (IHEP)(renyz@ihep.ac.cn)

Yang-Zhao Ren, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:

GECAM-B was triggered in-flight by GRB 260714B, at 2026-07-14T18:23:32.000 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45161), Fermi/LAT (Gupta et. Al., GCN #45162), and AstroSat/CZTI (Pathak et. al., GCN #45163).

According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 21.5 +2.5/-10.0 s.

The GECAM-B light curve can be found here:
https://www.bursthub.cn/gcn/2026/gecambgrb260714B.png

The time-averaged spectrum from T0-4 to T0 + 4 s is best fitted by a power law function. The power law index is -1.69 +0.09/-0.08. The event fluence (10-1000 keV) in this time interval is (6.06 +0.64/-0.67) E-06 erg/cm^2.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two micro-satellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).

Rosa L. Becerra (UNAM), Stéphane Basa (UAR Pytheas), Jean-Grégoire Ducoin (CPPM), William H. Lee (UNAM), Edilberto Aguilar-Ruiz (UNAM), Jean-Luc Atteia (IRAP), Camila Angulo (UNAM), Dalya Akl (NYUAD), Sarah Antier (IJCLAB), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Francis Fortin (IRAP), Leonardo García García (UNAM), Ramandeep Gill (UNAM), Noémie Globus (UNAM), Marion Guelfand (CPPM), Asuka Kuwata (UNAM), Massimiliano Lincetto (CPPM), Nikos Mandarakas (LAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), Margarita Pereyra (UNAM), Ny Avo Rakotondrainibe (LAM), Fredd Sánchez Álvarez (UNAM), Benjamin Schneider (LAM), Antonio de Ugarte Postigo (LAM), and Alan M. Watson (UNAM) report:

We imaged the field of the *Fermi* GRB 260714B (*Fermi* GBM Team GCN Circ. 45158; Mukherjee  et al., GCN Circ. 45161; Gupta et al., GCN Circ. 45162) also detected by AstroSat CZTI (Sharma et al., GCN Circ. 45163) using the DDRAGO two-channel wide-field imager on the COLIBRÍ telescope. We observed from 2026-07-16 03:46 to 05:23 UTC (from 1.39 to 1.46 days after the trigger) and obtained 59 and 71 minutes of exposure in the r and z filters, respectively.

The data were reduced, coadded and analysed with the ASU COLIBRÍ pipeline. The photometry was calibrated using nearby stars from the PanSTARRS DR1 catalog, is in the AB system, and is not corrected for Galactic extinction.

We detect an uncatalogued source, not present in the Legacy Survey catalog (Dey et al. 2019), located within the *Fermi*/GBM error circle (*Fermi* GBM Team, GCN Circ. 45158) at the following position:

RA(J2000) = 10:52:58.41 = 163.2434 deg,

Dec(J2000) = +46:49:20.0 = 46.8222 deg,

with an uncertainty of 0.5 arcsec. The position is 10.7 arcmin from the center of the *Fermi*/LAT localization (Gupta et al., GCN Circ. 45162), placing it outside the reported *Fermi*/LAT error region (6.6 arcmin).


The preliminary magnitudes derived for that source are:

r = 21.47 +/- 0.04,

z = 21.33 +/- 0.09.

The brightness and red color of the source are, however, consistent with those commonly observed in GRB afterglows, making it a plausible candidate for the optical counterpart of GRB 260714B. Combined with the high-energy emission detected by *Fermi*/LAT and the E*peak* determined from the subsequent analysis of the *Fermi*/GBM team (Mukherjee et al., GCN Circ. 45161), these properties motivate further follow-up. We encourage photometric monitoring to establish whether the source is fading, as well as spectroscopic observations to determine its distance.

We thank the staff of the Observatorio Astronómico Nacional at Sierra de San Pedro Mártir, as well as the technical and engineering teams at CEA, CPPM, IRAP, LAM, OHP, OSU Pytheas, and UNAM.

COLIBRÍ is an astronomical observatory developed and operated jointly by France (AMU, CNES and CNRS) and Mexico (UNAM and SECIHTI). It is located at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir, Baja California, Mexico.

U. Pathak (IITB), A. Arya (IITB), A. Goyal (IITB), Harsha K. H. (IUCAA), S.Salunke(IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long GRB 260714B which was also detected by Fermi/GBM (Fermi GBM team, GCN Circ. 45161), and Fermi LAT (Gupta et. al. , GCN Circ. 45162).

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2026-07-14 18:23:32.56 UTC. The measured peak count rate associated with the burst is 816 (+51, -54) counts/s above the background in the combined data of all quadrants, with a total of 3549 (+51, -54) counts. The local mean background count rate was 244 (+3, -3) counts/s. We measure a T90 of 10.7 (+0.2, -0.2) s from the cumulative CZT light curve. In the preliminary analysis, we find 543 Compton events associated with this event.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2026-07-14 18:23:29.78 UTC. The measured peak count rate associated with the burst is 1428 (+71, -82) counts/s above the background in the combined data of all quadrants, with a total of 6388 (+194, -285) counts. The local mean background count rate was 1225 (+5, -6) counts/s. We measure a T90 of 10.7 (+0.2, -0.2) s from the cumulative Veto light curve.

CZTI data products like interactive and downloadable light curves for this GRB can be found at: 
https://astrosat.iucaa.in/cift/cift_products/ET20260714T182326/ET20260714T182326_details.html

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb

U. Pathak (IITB), A. Arya (IITB), A. Goyal (IITB), Harsha K. H. (IUCAA), S.Salunke(IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long GRB 260714B which was also detected by Fermi/GBM (Fermi GBM team, GCN Circ. 45161), and Fermi LAT (Gupta et. al. , GCN Circ. 45162).

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2026-07-14 18:23:32.56 UTC. The measured peak count rate associated with the burst is 816 (+51, -54) counts/s above the background in the combined data of all quadrants, with a total of 3549 (+51, -54) counts. The local mean background count rate was 244 (+3, -3) counts/s. We measure a T90 of 10.7 (+0.2, -0.2) s from the cumulative CZT light curve. In the preliminary analysis, we find 543 Compton events associated with this event.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2026-07-14 18:23:29.78 UTC. The measured peak count rate associated with the burst is 1428 (+71, -82) counts/s above the background in the combined data of all quadrants, with a total of 6388 (+194, -285) counts. The local mean background count rate was 1225 (+5, -6) counts/s. We measure a T90 of 10.7 (+0.2, -0.2) s from the cumulative Veto light curve.

CZTI data products like interactive and downloadable light curves for this GRB can be found at: 
https://astrosat.iucaa.in/cift/cift_products/ET20260714T182326/ET20260714T182326_details.html

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb

R. Gupta (NASA/GSFC), and N. Di Lalla (Stanford University) report on behalf of the Fermi-LAT collaboration:

At 18:23:26.76 UT on July 14th, 2026, Fermi-LAT detected high-energy emission from GRB 260714B, which was also detected by Fermi-GBM (trigger 805746211/260714766, GCN #45158).

The best LAT on-ground location is found to be

RA, Dec = 163.12, 46.98 (J2000)

with an error radius of 0.11 deg (90 % containment, statistical error only).

This was 57 deg from the LAT boresight at the time of the trigger.

The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance.
The photon flux above 100 MeV in the time interval 0 - 400 s after the GBM trigger is (3.86 ± 0.91)E-5 ph/cm2/s. The estimated photon index above 100 MeV is -2.13 ± 0.23. The highest energy photon has an energy of 10 GeV and occurs at 200 s after trigger time.

The Fermi-LAT point of contact for this burst is Frédéric Piron (piron@in2p3.fr).

The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.

O. Mukherjee (USRA) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 18:23:26.76 UT on 14 July 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 260714B (trigger 805746211/260714766).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 166.40, Dec = 46.66 (J2000 degrees, equivalent to
J2000 11h 5m, +46d 39'), with a statistical uncertainty of 4.01 degrees.
(radius, 1-sigma containment, statistical only; there is additionally a
systematic error which we have characterized as a mixture of two Gaussians,
one with a radius of 1.8 degrees (52% contribution) and one with a radius
of 4.1 degrees (47% contribution) [A. Goldstein et al. 2020, ApJ, 895, 1]).

The angle from the Fermi LAT boresight is 56 degrees.

The GBM light curve consists of a single emission episode with multiple peaks, with a duration (T90) of about 12.5 s (50-300 keV). The time-averaged spectrum
from T0+0.002 to T0+18.435 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.14 +/- 0.01 and the cutoff energy,
parameterized as Epeak, is 660 +/- 3 keV.

The event fluence (10-1000 keV) in this time interval is
(2.51 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+5.2 s in the 10-1000 keV band is 17.1 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
805746211 at 18:23:26 on 14 July 2026 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position is:
RA(2000.0) = 163.3 deg
Decl.(2000.0) = 47.8 deg
The 1 sigma statistical error radius is 1.5 deg.
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB260714766/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB260714766/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB260714766/json

                        

The Fermi GBM team reports the detection of a likely LONG GRB

At 18:23:26 UT on 14 Jul 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260714B (trigger 805746211.760106 / 260714766).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 166.4, Dec = 46.7 (J2000 degrees, equivalent to J2000 11h 05m, 46d 42'), with a statistical uncertainty of 4.0 degrees.

The angle from the Fermi LAT boresight is 56.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260714766/quicklook/glg_skymap_all_bn260714766.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260714766/quicklook/glg_healpix_all_bn260714766.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260714766/quicklook/glg_lc_medres34_bn260714766.gif