TITLE:   GCN CIRCULAR
NUMBER:  35520
SUBJECT: GRB 240112A: GECAM detection of a burst
DATE:    24/01/12 07:03:01 GMT
FROM:    Chenwei Wang at IHEP <cwwang@ihep.ac.cn>

Chen-Wei Wang, Shao-Lin Xiong report on behalf of the GECAM team:
GECAM-B was triggered in-flight by a bright burst, tentatively named as GRB 240112A (see below),at 2024-01-12T05:41:25.850 UTC (denoted as T0).

GECAM-B localized this burst to the following position (J2000): 
Ra: 290.4 deg 
Dec: 18.4 deg
Err: 3.6 deg (1-sigma, statistical only)
We note that, although this in-flight location is very preliminary, it is generally consistent with SGR J1935+2154 within the error, therefore we suggest that it could be possibly from this magnetar. However, we cannot exclude the possibility of other origins at this moment.

According to the realtime alert data of GECAM-B, this burst mainly consists of two pulses
with a duration of about 3 s. The time-averaged spectrum from T0-0.2 to T0+3.8 s 
could be adequately fit by a power law with high energy exponential cutoff function 
with a fluence of about 5E-6 erg/cm^2 in 20-1000 keV.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/240112_lc.png

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 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).