GCN Circular 35266
Subject
GRB 231205A: GECAM-B detection of a short burst
Date
2023-12-05T03:48:51Z (5 months ago)
From
tanwj@ihep.ac.cn
Via
Web form
GRB 231205A: GECAM-B detection of a short burst
Wenjun Tan, Shaolin Xiong, report on behalf of the GECAM team:
GECAM-B was triggered in-flight by a short burst, GRB 231205A
at 2023-12-05T02:25:11.450 UTC(T0), which was also observed by
Fermi/GBM (Fermi/GBM team, GCN 35263).
According to the realtime alert data of GECAM-B, this burst consists
of one bright short pulse followed by weaker emission with a total
duration (T90) of about ~0.3 sec (30-1020 keV).
Using the automatic on-ground localization pipeline with the realtime alert data,
GECAM-B localized this burst to the following position (J2000):
Ra: 202.8 deg
Dec: 26.8 deg
Err: 6.1 deg (1-sigma, statistical only)
GECAM location is consistent with that of Fermi/GBM within the error.
The time-averaged spectrum of GECAM-B realtime data from about T0-0.05 s to T0 could be
adequately fit by a cut-off power-law with a fluence about 1.10E-6 erg/cm^2 in 20-1000 keV.
We note that these results are based on realtime alert data and thus very preliminary.
Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission originally consists of two microsatellites (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).