GCN Circular 35904
Subject
GRID detection of GRB 240229A (Updated Report)
Date
2024-03-08T16:54:57Z (2 months ago)
From
GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>
Via
Web form
Chenyu Wang, Zirui Yang and Longhao Li report on behalf of the GRID Collaboration:
GRID-03B and GRID-04 report the detection of the long-duration GRB 240229A, which was also detected by Fermi/GBM, CALET VZLUSAT-2, GRBAlpha and Glowbug (GCN Circular 35833, 35842, 35872, 35894 and 35897).
The event was triggered with GRID on 2024-02-29 at 14:07:08 UTC and had a double-peak structure. The measured burst duration (T90) in the 30-2000 keV range is approximately 25.0 ± 3.0 seconds.
The time-averaged spectrum of the first peak using GRID-04 realtime data from T+0 to T+10 sec is best fit by a power-law model with a fluence in the 10-1000 keV band is about 3.5259E-05 erg/cm2. The powerlaw index of the time-averaged spectrum is -1.51(-0.06,+0.06). 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/GRB240229A/GRID_240229A_ltcv.pdf. The GRID spectrum of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB240229A/GRID_240229A_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.