GRB 260710A
GCN Circular 45165
Subject
GRB 260710A: AstroSat CZTI detection
Date
2026-07-15T08:57:17Z (4 hours ago)
From
Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com>
Via
Web form
A. Arya (IITB), A. Goyal (IITB), S. Salunke(IUCAA), Harsha K. H. (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 short duration GRB 260710A which was also detected by Fermi (Fermi GBM team, GCN Circ. 45131), and Insight-HXMT/HE (Xing-Hao Luo et.al., GCN Circ. 45144).
The source was clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2026-07-10 12:58:43.56 UTC. The measured peak count rate associated with the burst is 331 (+50, -55) counts/s above the background in the combined data of all quadrants, with a total of 426 (+150, -166) counts. The local mean background count rate was 616 (+6, -6) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 for our detection.
The source was also faintly detected in the CZT detectors in the 20-200 keV energy range.
CZTI data products like interactive and downloadable light curves for this GRB can be found at:https://astrosat.iucaa.in/cift/cift_products/ET20260710T125843/ET20260710T125843_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
GCN Circular 45144
Subject
GRB 260710A: Insight-HXMT/HE detection
Date
2026-07-13T08:27:04Z (2 days ago)
From
Xinghao Luo at IHEP <2952704891@qq.com>
Via
Web form
Xing-Hao Luo, Chen-Wei Wang, Chao Zheng, and Shao-Lin Xiong (IHEP) report on behalf of the Insight-HXMT team:
At 2026-07-10T12:56:43.800 (T0), Insight-HXMT/HE detected the GRB 260710A, which is also detected by Fermi/GBM (Fermi GBM Team, GCN #45131).
The Insight-HXMT/HE light curve mainly consists of a single pulse with a T90 of 1.2 +1.2/-0.4 s. The 1s peak rate, measured from T0-0.3 s, is 727 cnts/sec. Insight-HXMT/HE detected a total of 841 counts from this burst.
The HXMT/HE light curve can be found here:
https://www.bursthub.cn/gcn/2026/hxmtgrb260710A.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/
GCN Circular 45138
Subject
GRB 260710A: Fermi GBM Detection
Date
2026-07-11T11:40:47Z (4 days ago)
From
Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>
Via
Web form
M. Dafcikova (MUNI) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 12:58:43.52 UT on 10 July 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 260710A (trigger 805381128/260710541).
The Final real-time localization was reported in GCN 45131.
The GBM light curve consists of a single peak with a duration (T90)
of about 1.9 s (50-300 keV). The time-averaged spectrum
from T0-0.16 to T0+1.94 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.93 +/- 0.03 and the cutoff energy,
parameterized as Epeak, is 139 +/- 3 keV.
The event fluence (10-1000 keV) in this time interval is
(2.17 +/- 0.09)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.38 s in the 10-1000 keV band is 30 +/- 3 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 98 +/- 3 keV, alpha = -0.71 +/- 0.02 and beta = -2.00 +/- 0.07.
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/"
GCN Circular 45131
Subject
GRB 260710A: Fermi GBM Final Real-time Localization
Date
2026-07-10T13:09:14Z (5 days ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 12:58:43 UT on 10 Jul 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260710A (trigger 805381128.521136 / 260710541).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 5.6, Dec = -85.0 (J2000 degrees, equivalent to J2000 00h 22m, -85d 00'), with a statistical uncertainty of 1.8 degrees.
The angle from the Fermi LAT boresight is 135.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260710541/quicklook/glg_skymap_all_bn260710541.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/bn260710541/quicklook/glg_healpix_all_bn260710541.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260710541/quicklook/glg_lc_medres34_bn260710541.gif