TITLE:   GCN CIRCULAR
NUMBER:  35413
SUBJECT: GRID detection of GRB 231215A
DATE:    23/12/22 09:12:33 GMT
FROM:    GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>

Chenyu Wang, Zirui Yang and Longhao Li report on behalf of the GRID Collaboration:

GRID-04 reports the detection of the long-duration GRB 231215A, which was also detected by Swift/BAT, AstroSat CZTI, AGILE, Fermi/GBM, Konus-Wind and GRBAlpha(GCN Circular 35343, 35352, 35361, 35369, 35377 and 35380).

The event was triggered with GRID on 2023-12-15 at 09:47:18.5 UTC. The measured burst duration (T90) in the 30-2000 keV range is approximately 17.0 ± 1.5 seconds.

The time-averaged spectrum of GRID-04 realtime data from T+0 to T+18 sec is best fit by a cutoff power-law model.  The index of the time-averaged spectrum is -0.576(-0.108,+0.114) with a fluence in the 10-1000 keV band is about 5.2488E-05 erg/cm2. All the quoted errors are at the 1-sigma confidence level.

The GRID light curve of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB231215A/GRID_231215A_ltcv.pdf. The GRID spectrum of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB231215A/GRID_231215A_spec_pl.pdf.

GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.