GRB 251214D
GCN Circular 43121
Subject
GRB 251214D: GECAM-B observation of a long burst
Date
2025-12-15T13:47:03Z (a day ago)
From
Xinghao Luo at SVOM/GRM <2952704891@qq.com>
Via
Web form
Xing-Hao Luo, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:
GECAM-B was triggered on-ground by GRB 251214D, at 2025-12-14T21:24:17.950 UTC (denoted as T0), which is also detected by AstroSat/CZTI (A. Arya et.al., GCN #43109).
According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 28.5 +6.5/-5.0 s.
The GECAM-B light curve can be found here:
https://www.bursthub.cn//admin/static/gecambgrb251214D.png
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).
GCN Circular 43109
Subject
GRB 251214D: AstroSat CZTI detection of a long burst
Date
2025-12-15T06:49:33Z (2 days ago)
From
Gaurav Waratkar at Caltech <gauravwaratkar@iitb.ac.in>
Via
Web form
A. Arya (IITB), A. Goyal (IITB), M. Tembhurnikar (IUCAA), S. Salunke (IUCAA), Harsha K. H. (IUCAA), G. Waratkar (Caltech/IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 251214D.
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2025-12-14 21:24:21.50 UTC. The measured peak count rate associated with the burst is 71 (+34, -11) counts/s above the background in the combined data of all quadrants, with a total of 576 (+192, -210) counts. The local mean background count rate was 264 (+3, -3) counts/s. Using cumulative rates, we measure a T90 of 16 (+3, -7) s.
The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2025-12-14 21:24:21.75 UTC. The measured peak count rate associated with the burst is 231 (+68, -36) counts/s above the background in the combined data of all quadrants, with a total of 1844 (+413, -469) counts. The local mean background count rate was 1211 (+7, -7) counts/s. We measure a T90 of 20 (+2, -8) s from the cumulative Veto light curve.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb