May 2026 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 42810] GRB 260307A: TERI Gamma-ray detection
by GCN Circulars 21 May '26

21 May '26

TITLE: GCN CIRCULAR NUMBER: 44682 SUBJECT: GRB 260307A: TERI Gamma-ray detection DATE: 26/05/21 14:06:50 GMT FROM: nicholasjkirschner(a)gmail.com Nicholas Kirschner (a), Daniel Shy (b), C.C. Cheung (b), Bernard Phlips (b), Michael Streicher (c), James Mason (c), Douglas M. Groves (c), Feng Zhang (c), and Willy Kaye (c) (a) National Research Council Research Associate resident at the U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (c) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on the International Space Station, reports the detection of GRB 260307A, which was also detected by Fermi/GBM (GCN 43939), Glowbug (GCN 43950), GECAM-B (GCN 43961), and CALET (GCN 43982). Using 1 Hz binning and adopting T0 = 2026-03-07T11:27:59.32Z, we observe three peaks at T0+1.375s, T0+3.125s, and T0+5.125s with peak excess count rate of 144, 116, 96 above the 100 cps baseline rate observed in nearby off-source intervals. The analysis results presented here are preliminary and currently lack a detailed response function. TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL) in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy range of 40 keV to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space Test Program STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility on the Columbus module. Analysis of TERI data at NRL is supported by the Office of Naval Research 6.1. [1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009 (arXiv:2408.04559). Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/44682. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42809] GRB 260225D: TERI Gamma-ray detection
by GCN Circulars 21 May '26

21 May '26

TITLE: GCN CIRCULAR NUMBER: 44681 SUBJECT: GRB 260225D: TERI Gamma-ray detection DATE: 26/05/21 14:06:05 GMT FROM: nicholasjkirschner(a)gmail.com Nicholas Kirschner (a), Daniel Shy (b), C.C. Cheung (b), Bernard Phlips (b), Michael Streicher (c), James Mason (c), Douglas M. Groves (c), Feng Zhang (c), and Willy Kaye (c) (a) National Research Council Research Associate resident at the U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (c) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on the International Space Station, reports the detection of GRB 260225D, which was also detected by Glowbug (GCN 43856), Konus-Wind (Trig_Time 19:51:32.84), SVOM/GRM (GCN 43885), and GRID (GCN 43890). Using 1 Hz binning and adopting T0 = 2026-02-25T19:51:28.768Z, we observe two peaks at T0+1.375s and 2.625s and peak excess count rate of 108 and 149 counts per second (cps) above the 128 cps baseline rate observed in nearby off-source intervals. The analysis results presented here are preliminary and currently lack a detailed response function. TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL) in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy range of 40 keV to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space Test Program STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility on the Columbus module. Analysis of TERI data at NRL is supported by the Office of Naval Research 6.1. [1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009 (arXiv:2408.04559). Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/44681. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42808] GRB 251118A: TERI Gamma-ray detection
by GCN Circulars 21 May '26

21 May '26

TITLE: GCN CIRCULAR NUMBER: 44680 SUBJECT: GRB 251118A: TERI Gamma-ray detection DATE: 26/05/21 14:05:27 GMT FROM: nicholasjkirschner(a)gmail.com Nicholas Kirschner (a), Daniel Shy (b), C.C. Cheung (b), Bernard Phlips (b), Michael Streicher (c), James Mason (c), Douglas M. Groves (c), Feng Zhang (c), and Willy Kaye (c) (a) National Research Council Research Associate resident at the U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (c) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on the International Space Station, reports the detection of GRB 251118A, which was also detected by Glowbug (GCN 42784), Fermi GBM (GCN 42743, 42745, 42783), Fermi LAT (GCN 42752), NuSTAR (GCN 42774), and GECAM-B (GCN 42779). Using 1 Hz binning, and adopting T0 = 2025-11-18T20:31:43.57Z, we observe two peaks at T0+4.5s and 40.5s. The analysis results presented here are preliminary and currently lack a detailed response function. TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL) in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy range of 40 keV to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space Test Program STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility on the Columbus module. Analysis of TERI data at NRL is supported by the Office of Naval Research 6.1. [1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009 (arXiv:2408.04559). Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/44680. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42807] GRB 251113A: TERI Gamma-ray detection
by GCN Circulars 21 May '26

21 May '26

TITLE: GCN CIRCULAR NUMBER: 44679 SUBJECT: GRB 251113A: TERI Gamma-ray detection DATE: 26/05/21 14:04:30 GMT FROM: nicholasjkirschner(a)gmail.com Nicholas Kirschner (a), Daniel Shy (b), C.C. Cheung (b), Bernard Phlips (b), Michael Streicher (c), James Mason (c), Douglas M. Groves (c), Feng Zhang (c), and Willy Kaye (c) (a) National Research Council Research Associate resident at the U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (c) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on the International Space Station, reports the detection of GRB 251113A, which was also detected by Glowbug (GCN 42689), Fermi GBM (GCN 42671, 42672), and AstroSat/CZTI (GCN 42688). Using 1 Hz binning, and adopting T0 = 2025-11-13T17:37:28.512ZZ we observe one peak at T0+14.5, with peak excess count rate of 64 cps above the 83 cps baseline rate observed in nearby off-source intervals. The analysis results presented here are preliminary and currently lack a detailed response function. TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL) in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy range of 40 keV to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space Test Program STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility on the Columbus module. Analysis of TERI data at NRL is supported by the Office of Naval Research 6.1. [1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009 (arXiv:2408.04559). Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/44679. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42806] GRB 260428A: TERI Gamma-ray detection
by GCN Circulars 21 May '26

21 May '26

TITLE: GCN CIRCULAR NUMBER: 44678 SUBJECT: GRB 260428A: TERI Gamma-ray detection DATE: 26/05/21 14:02:09 GMT FROM: nicholasjkirschner(a)gmail.com Nicholas Kirschner (a), Daniel Shy (b), C.C. Cheung (b), Bernard Phlips (b), Michael Streicher (c), James Mason (c), Douglas M. Groves (c), Feng Zhang (c), and Willy Kaye (c) (a) National Research Council Research Associate resident at the U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (b) U.S. Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (c) H3D, Inc., 812 Avis Dr., Ann Arbor, MI 48108, USA The cadmium zinc TElluride Radiation Imager (TERI) gamma-ray telescope [1], operating on the International Space Station, reports the detection of GRB 260411B, which was also detected by Fermi GBM (GCN 44415), AstroSat (GCN 44421), GECAM-B (GCN 44423), and SVOM/GRM (GCN 44424). Using 1 Hz binning, and adopting T0 = 2026-04-28T14:20:34.992Z, we observe one peak at T0+1.5s, with peak excess count rate of 49 above the 97 cps baseline rate observed in nearby offsource intervals. The analysis results presented here are preliminary and currently lack a detailed response function. TERI is an Office of Naval Research funded technology demonstrator for large-volume pixelated CdZnTe detectors developed, built, and operated by the U.S. Naval Research Laboratory (NRL) in conjunction with H3D, Inc. The pixelated CdZnTe detectors have an energy range of 40 keV to 3 MeV per pixel. It was launched on 2025 April 21 aboard the Department of Defense Space Test Program STP-H10 to the ISS. On the ISS, it is located on the SOX external payload facility on the Columbus module. Analysis of TERI data at NRL is supported by the Office of Naval Research 6.1. [1] Shy, Daniel, et al. "Development of the cadmium zinc TElluride Radiation Imager." Journal of Astronomical Telescopes, Instruments, and Systems 10.4 (2024): 044009-044009 (arXiv:2408.04559). Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/44678. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42805] Konus-Wind detection of GRB 260519C
by GCN Circulars 21 May '26

21 May '26

TITLE: GCN CIRCULAR NUMBER: 44677 SUBJECT: Konus-Wind detection of GRB 260519C DATE: 26/05/21 13:10:04 GMT FROM: Dmitry Svinkin at Ioffe Institute <dmitrysvinkin(a)gmail.com> D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, A. Tsvetkova, M. Ulanov, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 260519C (NuSTAR-ACS detection: Waratkar et al., GCN 44672) triggered Konus-Wind at T0=49536.443 s UT (13:45:36.443). The burst light curve shows a multipeaked structure which starts at ~T0-3.5 s and has a total duration of ~27 s. The emission is seen up to ~2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB260519_T49536/ As observed by Konus-Wind, the burst had the total fluence of 2.47(-0.15,+0.13)x10^-5 erg/cm2, and the 64-ms peak flux, measured from T0+2.192 s, of 2.45(-0.46,+0.46)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+24.832 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.78(-0.16,+0.18), the high energy photon index beta = -3.17(-0.94,+0.28), the peak energy Ep = 119(-7,+8) keV (chi2 = 96/96 dof). The spectrum near the maximum count rate (measured from T0+0.256 to T0+8.448 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.70(-0.11,+0.11) and Ep = 209(-10,+11) keV (chi2 = 91/78 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -3.6 (chi2 = 91/77 dof). All the quoted errors are at the 68% confidence level. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/44677. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42804] GRB 260520B: Fermi GBM Final Localization
by GCN Circulars 20 May '26

20 May '26

TITLE: GCN CIRCULAR NUMBER: 44676 SUBJECT: GRB 260520B: Fermi GBM Final Localization DATE: 26/05/20 18:00:48 GMT FROM: Cuán de Barra at UCD <cuan.debarra(a)ucdconnect.ie> The Fermi GBM team reports the detection of a likely LONG GRB "At 09:35:52.73 UT on 20 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB260520B (trigger 800962557/260520400). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 346.68, Dec = 39.68 (J2000 degrees, equivalent to J2000 23h 6m, -39d 40'), with a statistical uncertainty of 14 degrees. The angle from the Fermi LAT boresight is 21 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260520400/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260520400/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260520400/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/44676. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42803] GRB 260509A: SVOM/ECLAIRs refined analysis
by GCN Circulars 20 May '26

20 May '26

TITLE: GCN CIRCULAR NUMBER: 44675 SUBJECT: GRB 260509A: SVOM/ECLAIRs refined analysis DATE: 26/05/20 07:09:29 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> F. Daigne (IAP), F. Lacreu (IAP), U. Jacob (LUPM), M. Brunet (IRAP), D. Götz (CEA/Irfu), A. Saccardi (CEA/Irfu), H. Goto (RIKEN), D. Adrien (CEA) report on behalf of the SVOM/ECLAIRs team: Using the event-by-event data downloaded through the X-band ground station, we report further analysis of SVOM/ECLAIRs observations of GRB 260509A (SVOM burst-id sb26050905). The burst that triggered ECLAIRs onboard at T0 = 2026-05-09T21:51:09 UTC (GCN 44504) shows a multiple peaks lightcurve with a precursor starting at about T0-22 s for about 8 s. The burst duration is T90 = 14.3 +0.9/-1.3 s in the 4-120 keV energy band. The time-averaged spectrum from T0-1.4 s to T0+12.9 s in the energy range 5-120 keV is best fitted by a power-law model with a photon index -2.20 +/- 0.09. With this model, the 4-120 keV fluence is (4.1 +/- 0.3)E-7 erg/cm^2 and the 4-120 keV photon flux is 1.49 +/- 0.07 ph/cm^2/s. The value of the photon index indicates that this GRB is very soft and should probably be classified as an X-Ray Flash. The time-averaged spectrum of the precursor, from T0-22 s to T0-14.5 s in the energy range 5-20 keV is best fitted by a power-law model with a photon-index -3.0 +0.5/-0.6. It can also be fitted with a blackbody with temperature kT = 1.5 +0.4/-0.3 keV. All the quoted errors are at the 68% confidence level. The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. The SVOM/ECLAIRs point of contact for this burst is: F. Daigne (IAP) (daigne at iap.fr) View this GCN Circular online at https://gcn.nasa.gov/circulars/44675. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42802] GRB 260520A: Fermi GBM Final Localization
by GCN Circulars 20 May '26

20 May '26

TITLE: GCN CIRCULAR NUMBER: 44674 SUBJECT: GRB 260520A: Fermi GBM Final Localization DATE: 26/05/20 06:47:26 GMT FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com> The Fermi GBM team reports the detection of a likely LONG GRB "At 01:24:47.42 UT on 20 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260520A (trigger 800933092/260520059). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 191.01, Dec = -34.56 (J2000 degrees, equivalent to J2000 12h 44m, -34d 33’), with a statistical uncertainty of 14 degrees. The angle from the Fermi LAT boresight is 114 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260520059/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260520059/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260520059/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/44674. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 42801] GRB 260519D: Fermi GBM Final Localization Correction
by GCN Circulars 20 May '26

20 May '26

TITLE: GCN CIRCULAR NUMBER: 44673 SUBJECT: GRB 260519D: Fermi GBM Final Localization Correction DATE: 26/05/20 03:51:26 GMT FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com> The Fermi GBM team reports the detection of a likely LONG GRB "At 19:37:23.371 UT on 19 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260519D (trigger 800912248/260519818). This trigger was initially not classified as a GRB by the flight software, but is in fact a GRB. The on-ground calculated location, using the Fermi GBM trigger data, is RA = 87.37, Dec = -6.37 (J2000 degrees, equivalent to J2000 5h 49m, -6d 22’), with a statistical uncertainty of 14 degrees. The angle from the Fermi LAT boresight is 26 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260519818/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260519818/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260519818/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/44673. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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