GRB 251114B
GCN Circular 42739
Subject
GRB 251114B: Insight-HXMT/HE detection
Date
2025-11-18T15:58:27Z (4 days ago)
From
zhangjinpeng@ihep.ac.cn
Via
Web form
Jin-Peng Zhang, Chen-Wei Wang, Chao Zheng, and Shao-Lin Xiong (IHEP) report on behalf of the Insight-HXMT team:
At 2025-11-14T20:38:30.400 (T0), Insight-HXMT/HE detected a short-duration GRB 251114B, which is also detected by Fermi/GBM (Fermi GBM team, GCN #42687).
The Insight-HXMT/HE light curve mainly consists of a short pulse with a duration of about 2 s. The 1s peak rate, measured from T0-0.325 s, is 1373 cnts/sec. Insight-HXMT/HE detected a total of 3247 counts from this burst.
The Insight-HXMT /HE light curve can be found here:
https://www.bursthub.cn//admin/static/hxmtgrb251114B.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://www.hxmt.org
GCN Circular 42738
Subject
GRB 251114B: GECAM-B detection of a short burst
Date
2025-11-18T15:57:36Z (4 days ago)
From
zhangjinpeng@ihep.ac.cn
Via
Web form
Jin-Peng Zhang, Chen-Wei Wang, Chao Zheng, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:
GECAM-B was triggered in-flight by a short burst, GRB 251114B, at 2025-11-14T20:38:30.100 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN#42687).
According to the GECAM-B light curves in about 40-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 3.4 +1.6/-2.0 s.
The GECAM-B light curve can be found here:
https://www.bursthub.cn//admin/static/gecambgrb251114B.png
The time-averaged spectrum from T0-2 s to T0+2 s is best fitted by a power law function. The power law index is -1.97 +0.18/-0.16. The event fluence (10-1000 keV) in this time interval is (2.32 +0.22/-0.24)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).
GCN Circular 42687
Subject
GRB 251114B: Fermi GBM Final Real-time Localization
Date
2025-11-14T20:49:04Z (8 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 20:38:30 UT on 14 Nov 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251114B (trigger 784845515.202048 / 251114860).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 160.1, Dec = -85.2 (J2000 degrees, equivalent to J2000 10h 40m, -85d 12'), with a statistical uncertainty of 3.5 degrees.
The angle from the Fermi LAT boresight is 57.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251114860/quicklook/glg_skymap_all_bn251114860.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251114860/quicklook/glg_healpix_all_bn251114860.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251114860/quicklook/glg_lc_medres34_bn251114860.gif