GCN Circular 34448

Shaolin Xiong, Yanqiu Zhang, Yue Huang report on behalf of the GECAM team:

GECAM-B and GECAM-C were triggered in-flight by a long burst, GRB 230815B,
at 2023-08-15T16:07:29.150 UTC and 2023-08-15T16:07:29.350 UTC, respetively,
which was also observed by INTEGRAL/SPI-ACS and Konus-Wind.

According to the realtime alert data of GECAM-B and GECAM-C, this burst
mainly consists of a bright short pulse followed by a broad pulse with
a total duration (T90) of about ~30 sec (15-1000 keV).

Using the automatic on-ground localization pipeline with the realtime alert data, 
GECAM-B localized this burst to the following position (J2000): 
RA: 325.9 deg 
DEC: 13.2 deg
Err: 5.1 deg (1-sigma, statistical only)
The systematic error of this location is estimated to be several degrees.

The time-averaged spectrum of GECAM-B realtime data shows that it could be
adequately fit by a Band function with a fluence about 1.6E-5 erg/cm^2 in 20-1000 keV. 

We note that these results are based on realtime alert data and thus very preliminary. 
Refined analysis will be reported later.

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).