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

[vsnet-grb-info 43288] GRB 260629A: AstroSat CZTI detection
by GCN Circulars 04 Jul '26

04 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45074 SUBJECT: GRB 260629A: AstroSat CZTI detection DATE: 26/07/04 08:18:04 GMT FROM: Anuraag Arya at IIT Bombay <aryaanuraag910(a)gmail.com> Harsha K. H. (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 Short GRB 260629A which was also detected by Fermi (GBM Team, GCN Circ. 45056). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2026-06-29 15:06:59 UTC. The measured peak count rate associated with the burst is 108 (+70, -15) counts/s above the background in the combined data of three quadrants (out of four), with a total of 96 (+49, -50) counts. The local mean background count rate was 205 (+4, -6) counts/s. We measure a T90 of 0.89 (+0.45, -0.48) s from the cumulative CZT light curve. The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2026-06-29 15:06:59 UTC. The measured peak count rate associated with the burst is 378 (+65, -73) counts/s above the background in the combined data of all quadrants, with a total of 382 (+169, -188) counts. The local mean background count rate was 1283 (+7, -8) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 for our detection. CZTI data products like interactive and downloadable light curves for this GRB can be found at: http://astrosat.iucaa.in/cift/cift_products/520441618.77/S520441618.77_deta… 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/45074. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43287] EP260703a: EP-FXT follow-up observation
by GCN Circulars 04 Jul '26

04 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45073 SUBJECT: EP260703a: EP-FXT follow-up observation DATE: 26/07/04 04:58:22 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> R.-Z. Li (YNAO, CAS), G. L. Huang (IHEP, CAS), Z.-Y. Jian (HKU), X. Mao and Y. Liu (NAO, CAS) on behalf of the Einstein Probe (EP) team: EP-FXT performed a follow-up observation of EP260703a (R.-Z. Li et al., GCN 45070) starting at 2026-07-03T14:23:53 (UTC), approximately 11.17 hours after the WXT detection. With an exposure time of 6.1 ks, no significant X-ray source was detected within the 2.7 arcmin radius of the EP-WXT position. The derived 0.5-10 keV upper limit is about 7.6e-14 erg cm^-2 s^-1 (90% C.L.). Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/45073. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43286] GRB 260704A: SVOM detection of a possible GRB
by GCN Circulars 04 Jul '26

04 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45072 SUBJECT: GRB 260704A: SVOM detection of a possible GRB DATE: 26/07/04 04:49:49 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> W.J XIE (NAOC), C. PLASSE (HKU), Y.H CHENG (YNU), X.TIAN (GXU) report on behalf of the SVOM mission team: At 2026-07-04T03:41:05 UTC (T0), SVOM/ECLAIRs triggered and located an a possible GRB (SVOM burst-id sb26070403).The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network. The burst was only detected by the Image Trigger (IMT), which produced a sequence of 3 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 7.66 in the [5-20] keV energy band over a time window of 40.96 seconds starting at 2026-07-04T03:40:24. The localization of the best alert is R.A., Dec. 318.5239, -25.6141 degrees (J2000) with a 90% confidence level (C.L.) radius of 10.25 arcmin (including systematic error of 2 arcmin added in quadrature). There is a high proper motion star LP 873-16 in the ECLAIRs error box. SVOM slewed to the burst. SVOM/MXT began observing the field at 2026-07-04T03:43:24 UTC, 139 seconds after T0. Using onboard processed data we found an uncatalogued X-ray source located at R.A., Dec. 318.7072, -25.5102 degrees: R.A. (J2000) = 21h14m49.74s Dec. (J2000) = -25d30m36.89s with a 90% C.L. radius of 33.97 arcseconds. This location is 11.72 arcminutes from the ECLAIRs onboard position. This position may be improved as more data is received. 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. SVOM/ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. SVOM/GRM was developed by the Institute of High Energy Physics (IHEP) of CAS. SVOM/MXT was developed jointly by CNES, CEA-IRFU, CNRS-IJCLab, University of Leicester, MPE. The Burst Advocate (BA) on shift for this alert is : yhcheng(a)mail.ynu.edu.cn Please contact the BA by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/45072. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43285] GRB 260703B: Fermi GBM Final Localization
by GCN Circulars 03 Jul '26

03 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45071 SUBJECT: GRB 260703B: Fermi GBM Final Localization DATE: 26/07/03 19:21:18 GMT FROM: Angus Jameson <abj0023(a)uah.edu> The Fermi GBM team reports the detection of a likely LONG GRB "At 02:25:05.66 UT on 03 July 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260703B (trigger 804738310/260703101). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 310.5, Dec = 47.9 (J2000 degrees, equivalent to J2000 20h 42m, +47d 54'), with a statistical uncertainty of 5.1 degrees. The angle from the Fermi LAT boresight is 19 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703101/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703101/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703101/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/45071. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43284] EP260703a: EP-WXT detection of a fast X-ray transient
by GCN Circulars 03 Jul '26

03 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45070 SUBJECT: EP260703a: EP-WXT detection of a fast X-ray transient DATE: 26/07/03 12:44:47 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> R.-Z. Li (YNAO, CAS), G. L. Huang (IHEP, CAS), Z.-Y. Jian (HKU), X. Mao and Y. Liu (NAO, CAS) on behalf of the Einstein Probe (EP) team: We report on the detection of a fast X-ray transient, designated EP260703a (notice ID: 11900792707), by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission . The transient was identified in the telemetry data. The transient started at 2026-07-03T03:13:57 (UTC) and lasted for about 50s, with a peak flux of ~ 2 x 10^(-9) erg cm^-2 s^-1 in 0.5-4 keV. The position of the transient is R.A. = 274.7265 deg, Dec. = -62.6004 (J2000), with an uncertainty radius of 2.7 arcmin in radius (90% confidence level, including both statistical and systematic uncertainties). There are no known X-ray sources in the WXT error circle. The average WXT 0.5-4 keV spectrum can be fitted by an absorbed power-law model with a fixed Galactic hydrogen column density of 5.56×10^20 cm^-2 and a photon index of 0.22 (-1.17/+1.08). The derived average unabsorbed 0.5-4 keV flux is 1.46 (-0.81/+2.22) x 10^(-9) erg cm^-2 s^-1. The uncertainties are at the 90% confidence level for the above parameters. Follow-up observations by EP-FXT will be arranged. Launched on 2024 January 9, Einstein Probe is a space-based X-ray observatory designed to monitor the dynamic X-ray sky and perform rapid follow-up observations of newly discovered transients (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/45070. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43283] EP260628b: EP-WXT detection of an X-ray transient and EP-FXT follow-up observation
by GCN Circulars 03 Jul '26

03 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45069 SUBJECT: EP260628b: EP-WXT detection of an X-ray transient and EP-FXT follow-up observation DATE: 26/07/03 07:34:40 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> C. Y. Dai (NJU), X. Mao, H. N. Yang, C. C. Jin (NAO, CAS) on behalf of the Einstein Probe (EP) team: We report on the detection of an X-ray transient, designated EP260628b, by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The transient was identified in the telemetry data. The transient started at 2026-06-28T10:04:53 (UTC) and lasted for about 1000 s. The position of the transient is R.A. = 327.606 deg, Dec. = -29.324 deg (J2000), with an uncertainty radius of 2.6 arcmin (90% confidence level, including both statistical and systematic uncertainties). The average WXT 0.5-4 keV spectrum can be fitted by an absorbed power-law model with a fixed Galactic hydrogen column density of 2.0 x 10^20 cm^-2 and a photon index of 1.40 +/- 0.46. The derived average unabsorbed 0.5-4 keV flux is 7.18 (-1.80/+2.41) x 10^-11 erg cm^-2 s^-1. The uncertainties are at the 90% confidence level for the above parameters. EP-FXT performed a follow-up observation of EP260628b starting at 2026-06-29T09:55:12 (UTC), approximately 1 day after the WXT detection. With an exposure time of 1.7 ks, two X-ray sources were detected within the 2.6 arcmin radius of the EP-WXT position. The first source (EPF_J215025.7-291939) is located at R.A. = 327.6070 deg, Dec. = -29.3276 deg (J2000), with an uncertainty radius of about 10 arcsec (90% C.L., including statistical and systematic uncertainties). The angular separation from the WXT position is 0.28 arcmin. Its 0.5-10 keV spectrum can be fitted by an absorbed power-law model with a fixed Galactic hydrogen column density of 2.0 x 10^20 cm^-2 and a photon index of 3.09 (-0.59/+0.59). The derived unabsorbed 0.5-10 keV flux is 1.61 (-0.30/+0.45) x 10^-13 erg cm^-2 s^-1. The second source (EPF_J215025.3-291849) is located at R.A. = 327.6054 deg, Dec. = -29.3136 deg (J2000), with an uncertainty radius of about 10 arcsec. The angular separation from the WXT position is 0.56 arcmin. Its 0.5-10 keV spectrum can also be fitted by an absorbed power-law model with a fixed Galactic hydrogen column density of 2.0 x 10^20 cm^-2 and a photon index of 2.61 (-0.55/+0.60). The derived unabsorbed 0.5-10 keV flux is 1.71 (-0.38/+0.62) x 10^-13 erg cm^-2 s^-1. No known X-ray sources are found within either FXT error circle. Further follow-up observations by EP-FXT will be arranged. Given that the two FXT sources are located close to each other and show comparable X-ray fluxes and similar spectral properties, the association with the WXT transient and the nature of the event remain unclear. Further multi-wavelength follow-up observations are encouraged. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/45069. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43282] Fermi trigger No 804738310: Global MASTER-Net observations report
by GCN Circulars 03 Jul '26

03 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45068 SUBJECT: Fermi trigger No 804738310: Global MASTER-Net observations report DATE: 26/07/03 04:33:55 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), M. Segura, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAGH robotic telescope [1] located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB260703.10 (trigger No 804738310,21h 00m 43.92s , +48d 28m 01.2s, R=19.2) errorbox 4283 sec after notice time and 4323 sec after trigger time at 2026-07-03 03:37:09 UT, with upper limit up to 17.8 mag. Observations started at twilight. The observations began at zenith distance = 69 deg. The sun altitude is -13.3 deg. The galactic latitude b = 1 deg., longitude l = 89 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3412721 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 4354 | 2026-07-03 03:37:09 | MASTER-OAGH | (22h 18m 30.52s , +65d 39m 41.5s) | C | 60 | 17.0 | 4354 | 2026-07-03 03:37:09 | MASTER-OAGH | (22h 32m 37.85s , +65d 00m 33.9s) | C | 60 | 17.3 | 4430 | 2026-07-03 03:38:25 | MASTER-OAGH | (22h 18m 28.10s , +65d 40m 16.0s) | C | 60 | 17.0 | 4430 | 2026-07-03 03:38:25 | MASTER-OAGH | (22h 32m 35.76s , +65d 01m 08.8s) | C | 60 | 17.4 | 6859 | 2026-07-03 04:18:54 | MASTER-OAGH | (22h 12m 20.69s , +67d 31m 22.6s) | C | 60 | 17.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/45068. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43281] Fermi GRB 260703A: Global MASTER-Net observations report
by GCN Circulars 03 Jul '26

03 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45067 SUBJECT: Fermi GRB 260703A: Global MASTER-Net observations report DATE: 26/07/03 04:32:19 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), M. Segura, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAGH robotic telescope [1] located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 260703A ( Fermi GBM team, GCN 45066) errorbox 4679 sec after notice time and 4712 sec after trigger time at 2026-07-03 03:33:19 UT, with upper limit up to 18.7 mag. Observations started at twilight. The observations began at zenith distance = 72 deg. The sun altitude is -12.7 deg. The galactic latitude b = 2 deg., longitude l = 113 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3412712 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 4742 | 2026-07-03 03:33:19 | MASTER-OAGH | (22h 55m 39.05s , +66d 56m 42.8s) | C | 60 | 16.9 | 4742 | 2026-07-03 03:33:19 | MASTER-OAGH | (22h 40m 24.15s , +67d 36m 09.7s) | C | 60 | 16.4 | 4815 | 2026-07-03 03:34:32 | MASTER-OAGH | (22h 55m 44.27s , +66d 55m 36.7s) | C | 60 | 17.0 | 4815 | 2026-07-03 03:34:32 | MASTER-OAGH | (22h 40m 30.26s , +67d 35m 03.6s) | C | 60 | 16.6 | 4891 | 2026-07-03 03:35:48 | MASTER-OAGH | (23h 55m 18.75s , +68d 50m 07.3s) | C | 60 | 17.2 | 4891 | 2026-07-03 03:35:48 | MASTER-OAGH | (23h 38m 45.84s , +69d 30m 09.3s) | C | 60 | 16.7 | 4972 | 2026-07-03 03:37:09 | MASTER-OAGH | (22h 18m 30.52s , +65d 39m 41.5s) | C | 60 | 17.0 | 4972 | 2026-07-03 03:37:09 | MASTER-OAGH | (22h 32m 37.85s , +65d 00m 33.9s) | C | 60 | 17.3 | 5048 | 2026-07-03 03:38:25 | MASTER-OAGH | (22h 18m 28.10s , +65d 40m 16.0s) | C | 60 | 17.0 | 5048 | 2026-07-03 03:38:25 | MASTER-OAGH | (22h 32m 35.76s , +65d 01m 08.8s) | C | 60 | 17.4 | 7477 | 2026-07-03 04:18:54 | MASTER-OAGH | (22h 27m 21.10s , +66d 52m 48.7s) | C | 60 | 18.5 | 7477 | 2026-07-03 04:18:54 | MASTER-OAGH | (22h 12m 20.69s , +67d 31m 22.6s) | C | 60 | 17.8 | 7552 | 2026-07-03 04:20:09 | MASTER-OAGH | (23h 26m 37.26s , +70d 41m 38.4s) | C | 60 | 18.6 | 7552 | 2026-07-03 04:20:09 | MASTER-OAGH | (23h 08m 47.46s , +71d 21m 01.8s) | C | 60 | 18.0 | 7635 | 2026-07-03 04:21:31 | MASTER-OAGH | (00h 00m 28.54s , +70d 44m 10.6s) | C | 60 | 18.5 | 7635 | 2026-07-03 04:21:31 | MASTER-OAGH | (23h 42m 37.15s , +71d 23m 51.5s) | C | 60 | 17.8 | 7710 | 2026-07-03 04:22:47 | MASTER-OAGH | (22h 52m 44.70s , +70d 41m 44.6s) | C | 60 | 18.7 | 7784 | 2026-07-03 04:24:01 | MASTER-OAGH | (22h 52m 44.99s , +70d 41m 43.6s) | C | 60 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/45067. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43280] GRB 260703A: Fermi GBM Final Localization
by GCN Circulars 03 Jul '26

03 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45066 SUBJECT: GRB 260703A: Fermi GBM Final Localization DATE: 26/07/03 03:47:10 GMT FROM: Matt Godwin <msg0028(a)uah.edu> The Fermi GBM team reports the detection of a likely SHORT GRB "At 02:14:47.19 UT on 03 July 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260703A (trigger 804737692/260703094). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 350.51, Dec = 63.36 (J2000 degrees, equivalent to J2000 23h 22m, +63d 21'), with a statistical uncertainty of 6.72 degrees. The angle from the Fermi LAT boresight is 29 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703094/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703094/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703094/…" View this GCN Circular online at https://gcn.nasa.gov/circulars/45066. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43279] GRB 260610B: VLA detection
by GCN Circulars 02 Jul '26

02 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45065 SUBJECT: GRB 260610B: VLA detection DATE: 26/07/02 20:07:05 GMT FROM: Tanmoy Laskar at U of Utah <tanmoylaskar(a)gmail.com> T. Laskar (Utah), B. P. Gompertz (Birmingham), G. E. Anderson (Curtin), A. Levan (Radboud and Warwick), Daniele Malesani (DAWN/NBI and Radboud), Steve Schulze (Weizmann), Nial Tanvir (Leicester), A. J. van der Horst (GWU) report on behalf of a larger collaboration: “We observed GRB 260610B (Fermi GBM team, GCN 44891; O'Neill et al., GCN 44903) with the Karl G. Jansky Very Large Array (VLA) at multiple frequencies beginning on 2026 June 13 at 07:23 UT (2.89 days after the burst). In preliminary analysis, we detect the radio counterpart (Laskar et al., GCN 44941) at 9 GHz with a flux density of ~ 0.4mJy at the position: RA(J2000) = 14:32:38.25 +/- 0.01” Dec(J2000) = 27:00:17.64 +/- 0.01” This is consistent with the optical position (O'Neill et al., GCN 44903) and radio position (Laskar et al., GCN 44941). Further observations are planned. We thank the VLA staff for scheduling and executing these observations.” View this GCN Circular online at https://gcn.nasa.gov/circulars/45065. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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