GRB 260120A
GCN Circular 43508
Subject
GRB 260120A: AstroSat CZTI detection
Date
2026-01-24T11:33:06Z (2 months ago)
From
Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com>
Via
Web form
Harsha K. H. (IUCAA), M. Tembhurnikar (IUCAA), S. Salunke (IUCAA), A. Arya (IITB), A. Goyal (IITB), 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 GRB 260120A which was also detected by Fermi GBM (Fermi GBM Team, GCN Circ. 43467), and GECAM-B (Guo et al., GCN Circ. 43505).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-01-20 04:01:55.50 UTC. The measured peak count rate associated with the burst is 264 (+132, -24) counts/s above the background in the combined data of three quadrants (out of four), with a total of 345 (+83, -77) counts. The local mean background count rate was 189 (+3, -7) counts/s. Using cumulative rates, we measure a T90 of 3.1 (+1.1, -0.8) 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 2026-01-20 04:01:54.79 UTC. The measured peak count rate associated with the burst is 246 (+62, -64) counts/s above the background in the combined data of all quadrants, with a total of 625 (+185, -199) counts. The local mean background count rate was 1120 (+5, -6) counts/s. We measure a T90 of 4.2 (+1.3, -1.5) 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
GCN Circular 43505
Subject
GRB 260120A: GECAM-B observation
Date
2026-01-23T15:39:23Z (2 months ago)
From
guohx@ihep.ac.cn
Via
Web form
Hao-Xuan Guo, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team:
GECAM-B was triggered in-flight by GRB 260120A, at 2026-01-20T04:01:55.800 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #43467).
According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 2.3 +1.1/-0.7 s.
The GECAM-B light curve can be found here:
https://www.bursthub.cn//admin/static/gecambgrb260120A.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 43467
Subject
GRB 260120A: Fermi GBM Final Real-time Localization
Date
2026-01-20T04:12:25Z (2 months ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 04:01:54 UT on 20 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260120A (trigger 790574519.95612 / 260120168).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 345.9, Dec = -24.7 (J2000 degrees, equivalent to J2000 23h 03m, -24d 41'), with a statistical uncertainty of 2.5 degrees.
The angle from the Fermi LAT boresight is 72.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260120168/quicklook/glg_skymap_all_bn260120168.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260120168/quicklook/glg_healpix_all_bn260120168.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260120168/quicklook/glg_lc_medres34_bn260120168.gif