GRB 260831A
GCN Circular 45502
Subject
GRB 260831A: GECAM-B observation
Date
2026-09-03T15:12:15Z (20 days ago)
From
Jin-Ye Luo <jy_luo2002@163.com>
Via
Web form
Jin-Ye Luo, Chen-Wei Wang, Yue Wang, Chao Zheng, Zheng-Hang Yu, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:
GECAM-B was triggered in-flight by GRB 260831A at 2026-08-31T04:09:02.000 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45473).
According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of a single pulse with a duration (T90) of 4 +2/-2 s.
The GECAM-B light curve can be found here:
https://www.bursthub.cn/gcn/2026/gecambgrb260831A.png
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 45473
Subject
GRB 260831A: Fermi GBM Final Real-time Localization
Date
2026-08-31T04:17:21Z (23 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 04:09:00 UT on 31 Aug 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260831A (trigger 809842145.925584 / 260831173).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 220.0, Dec = -7.2 (J2000 degrees, equivalent to J2000 14h 39m, -7d 12'), with a statistical uncertainty of 6.5 degrees.
The angle from the Fermi LAT boresight is 84.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260831173/quicklook/glg_skymap_all_bn260831173.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/bn260831173/quicklook/glg_healpix_all_bn260831173.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260831173/quicklook/glg_lc_medres34_bn260831173.gif