GRB 261011B
GCN Circular 45938
Subject
GRB 261011B: GECAM-B observation
Date
2026-10-13T12:26:52Z (5 hours ago)
From
Jin-Ye Luo <jy_luo2002@163.com>
Via
Web form
Jin-Ye Luo, Chen-Wei Wang, Yue Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:
GECAM-B was triggered in-flight by GRB 261011B at 2026-10-11T17:26:53.000 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45910).
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 9.5 +2.5/-3.5 s.
The GECAM-B light curve can be found here:
https://www.bursthub.cn/gcn/2026/gecambgrb261011B.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 45910
Subject
GRB 261011B: Fermi GBM Final Localization
Date
2026-10-11T21:40:10Z (2 days ago)
From
Eva MP at INAOE <eva.palafox@gmail.com>
Via
Web form
The Fermi GBM team reports the detection of a likely LONG GRB
"At 17:26:50.57 UT on 11 October 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 261011B (trigger 813432415/261011727).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 185.63, Dec = -38.37 (J2000 degrees, equivalent to J2000 12h 23m, -38d 22')
with a statistical uncertainty of 4.2 degrees.
The angle from the Fermi LAT boresight is 83 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261011727/quicklook/glg_skymap_all_bn261011727.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/bn261011727/quicklook/glg_healpix_all_bn261011727.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261011727/quicklook/glg_lc_medres34_bn261011727.gif"