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

[vsnet-grb-info 43341] GRB 260708A: Kilonova-Catcher optical afterglow detection
by GCN Circulars 09 Jul '26

09 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45127 SUBJECT: GRB 260708A: Kilonova-Catcher optical afterglow detection DATE: 26/07/09 17:01:32 GMT FROM: Damien Turpin at CEA-Saclay <dturpin-astro(a)hotmail.com> M. Freeberg (KNC), D. Turpin (CEA-Saclay/Irfu), C. Andrade(UMN), S. Antier (IJCLab), M. Coughlin (UMN),S. Karpov (FZU), P. Hello (IJCLAB), M. Pillas (IAP) on behalf of the GRANDMA/Kilonova-Catcher collaboration: We observed the field of GRB 260708A detected by Fermi/GBM (Fermi GBM team, GCN 45115; GCN 45124) and Fermi/LAT (Holzmann Airasca et al., GCN 45117) with the GRANDMA citizen science project Kilonova-catcher (KNC). Our observations were performed with a iTtelescope T30 located at Siding Spring Observatory operated by M. Freeberg. Our observations started at TGRB+1.17 days and were taken with the Johnson/Cousins R filter. In our stacked frames, we clearly detect the optical counterpart reported by MASTER (Shilova et al., GCN 45123). We report part of our follow-up results in the table below : | Tmid-TGRB (days) | Exp (s) | Filter | Magnitude | Instrument | | ------------ | ------------ |------------ |------------ |------------ | | 1.18 | 3 x 300s | R (Vega) | 18.93 +/- 0.14 | iT30 | Given the significant fading behavior compared to the previous MASTER epoch, we considered this optical candidate is the optical afterglow of the energetic burst GRB 260708A. Further observations are ongoing. All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). Images obtained with the Johnson-cousins filters were calibrated using the GAIA DR3 synphot catalog. We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023). GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/) View this GCN Circular online at https://gcn.nasa.gov/circulars/45127. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43340] GRB 260708A: GECAM-B observation of a burst
by GCN Circulars 09 Jul '26

09 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45126 SUBJECT: GRB 260708A: GECAM-B observation of a burst DATE: 26/07/09 16:35:09 GMT FROM: renyz16607(a)163.com Yang-Zhao Ren, Chen-Wei Wang, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered in-flight by GRB 260708A, at 2026-07-08T10:11:17.650 UTC (denoted as T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #45115), and Fermi/LAT (Fermi LAT team, GCN #45117). According to the GECAM-B light curves in about 70-6000 keV, this burst mainly consists of multiple pulses with a duration (T90) of 46.5 +5.0/-6.5 s. The GECAM-B light curve can be found here: https://www.bursthub.cn//admin/static/gecambgrb260708A.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). View this GCN Circular online at https://gcn.nasa.gov/circulars/45126. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43339] IceCube-260708A: One candidate from the Zwicky Transient Facility
by GCN Circulars 09 Jul '26

09 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45125 SUBJECT: IceCube-260708A: One candidate from the Zwicky Transient Facility DATE: 26/07/09 16:21:49 GMT FROM: Robert David Stein at JSI <rdstein(a)umd.edu> Robert Stein (JSI), Tomas Ahumada (Noirlab), Mansi Kasliwal (Caltech), Jesper Sollerman (Stockholm), Cristobal Zilleruelo Cañas (DESY), Jannis Necker (Leiden University), Akshay Eranhalodi (DESY), and Anna Franckowiak (Ruhr University Bochum) report, On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: As part of the ZTF neutrino follow up program (Stein et al. 2023), we observed the localization region of the neutrino event IceCube-260708A (Zegarelli et. al, GCN 45120) with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). We started observations in the g- and r-band beginning at 2026-07-09 08:12 UTC, approximately 14.9 hours after event time. We covered 23.8% (0.2 sq deg) of the reported localization region at least twice. This estimate accounts for chip gaps. Each exposure was 300s with a typical depth of 21.0 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019, Stein et al. 2021) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019) . We are left with the following high-significance transient candidate by our pipeline, lying within the 90.0% localization of the skymap. +--------------------------------------------------------------------------------+ | ZTF Name | IAU Name | RA (deg) | DEC (deg) | Filter | Mag | MagErr | +--------------------------------------------------------------------------------+ | ZTF26abfurzw | AT2026kuv | 292.8653948 | -15.1344488 | r | 20.11 | 0.07 | +--------------------------------------------------------------------------------+ ZTF26abfurzw/AT 2026kuv was discovered by GOTO on 2026-04-20, and reported to TNS. ATLAS forced photometry reveals a lightcurve rising since discovery, later peaking at 17.4 mag at the beginning of May. The source has since slowly faded. The source was detected in our ZTF ToO observations, and the photometry confirms that the source is now very red (g-r = 1) and faded substantially from peak. There were no previous ZTF survey detections, because the source lies in a chip gap for the survey footprint. The photometric properties (rise, fade, and late-time colour) of AT 2026kuv appear consistent with a supernova. Neutrino emission in a post-peak supernova would be plausible if there were CSM interaction in the source. We encourage spectroscopic observations of this source to confirm its nature, and to search for evidence of CSM interaction. Further monitoring of this field will continue as part of the ZTF neutrino follow-up program (Stein et al. 2023), and we are planning additional follow-up of AT 2026kuv. ZTF and GROWTH are worldwide collaborations comprising Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan; OKC, Sweden; DZA, Germany. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering is performed with the nuztf (Stein et al. 2021, https://github.com/desy-multimessenger/nuztf ). View this GCN Circular online at https://gcn.nasa.gov/circulars/45125. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43338] GRB 260708A: Fermi-GBM observation
by GCN Circulars 09 Jul '26

09 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45124 SUBJECT: GRB 260708A: Fermi-GBM observation DATE: 26/07/09 15:29:24 GMT FROM: Christian Malacaria at INAF-OAR <cmalacaria.astro(a)gmail.com> C. Malacaria (INAF-OAR) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 10:11:16.89 UT on 08 July 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260708A (trigger 805198281/260708424). The Final real-time localization was reported in GCN 45115. Fermi-LAT also detected GRB 260708A (GCN 45117). The GBM light curve displays a sharp peak with a duration (T90) of about 62 s (50-300 keV). The time-averaged spectrum from T0+0.5 to T0+49.7 s is best fit by a power law function with a power law index of -1.86 +/- 0.01 . The event fluence (10-1000 keV) in this time interval is (2.14 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.5 s in the 10-1000 keV band is 19.6 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/" View this GCN Circular online at https://gcn.nasa.gov/circulars/45124. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43337] Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection
by GCN Circulars 09 Jul '26

09 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45123 SUBJECT: Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection DATE: 26/07/09 10:23:14 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> M.Shilova, K.Zhirkov, V.Lipunov, A.Kuznetsov, P.Balanutsa, G.Antipov, I.Panchenko, N.Tiurina, Ya.Kechin, E.Gorbovskoy, V.Senik, A.Chasovnikov, V.Topolev,D.Vlasenko,A.Sankovich, I.Gorbunov, V.Fedorova, A.Telnova (Lomonosov MSU), F.Podesta, M.J. Segura, C.Francile, R.Podesta, E. Gonzalez (OAFA, SJNU), D.Buckley (SAAO), A.Sosnovskij (CrAO RAS), N.Budnev, O.Gress (ISU), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich (Blagoveschensk Educational StateUniversity) R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez,J.Martinez,A.R.Corella, J.Tanori, L. Villalobos, L.H.Rodriguez (INAOE, Guillermo Haro AstrophysicsObservatory) MASTER-OAFA and MASTER-SAAO robotic telescopes of MASTER Global Robotic Net [1-4] was pointed to the Fermi LAT GRB 260708A (Holzmann Airasca et al. GCN 45117, trigger 2026-07-08 10:11:16.89 UT, RA, Dec = 225.61, -44.07 +-0.27 (J2000)) at 2026-07-08 22:40:00 UT (Lipunov et al. 45119). There is optical counterpart of GRB 260708A MASTER OT J150237.02-435307.7 https://www.wis-tns.org/object/2026stf discovered by MASTER auto-detection system [1-4] at 2026-07-08 22:42:34.272UT with unfiltere m~17.6m. The typical light curve points to GRB source. spectral observations is required. [1] Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L [2] Lipunov et al. 2022, Universe, Vol. 8(5), id.271 [3] Lipunov et a. 2019, ARep, vol.63, 293 [4] Lipunov et al. 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics,Lomonosov MSU PRESS, 591pp. http://www.pereplet.ru/lipunov/625.html#625 View this GCN Circular online at https://gcn.nasa.gov/circulars/45123. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43336] IceCube Alert 260709A: Global MASTER-Net observations report
by GCN Circulars 09 Jul '26

09 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45122 SUBJECT: IceCube Alert 260709A: Global MASTER-Net observations report DATE: 26/07/09 01:40:15 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) was pointed to the IceCube Alert 260709A (trigger No 7869742,19h 31m 14.40s , -15d 10m 12.0s, R=0.47) errorbox 26953 sec after notice time and 27118 sec after trigger time at 2026-07-09 00:49:40 UT, with upper limit up to 19.4 mag. The observations began at zenith distance = 59 deg. The sun altitude is -38.3 deg. The galactic latitude b = -16 deg., longitude l = 24 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3421037 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 27148 | 2026-07-09 00:49:40 | MASTER-OAFA | (19h 30m 06.32s , -15d 10m 17.3s) | C | 60 | 16.9 | 27208 | 2026-07-09 00:49:40 | MASTER-OAFA | (19h 30m 06.31s , -15d 10m 17.2s) | C | 180 | 17.4 | Coadd 27228 | 2026-07-09 00:51:00 | MASTER-OAFA | (19h 30m 06.41s , -15d 11m 45.7s) | C | 60 | 17.0 | 27305 | 2026-07-09 00:52:17 | MASTER-OAFA | (19h 30m 09.68s , -15d 10m 37.9s) | C | 60 | 17.4 | 27402 | 2026-07-09 00:53:54 | MASTER-OAFA | (19h 30m 03.99s , -15d 11m 03.0s) | C | 60 | 18.0 | 27462 | 2026-07-09 00:53:54 | MASTER-OAFA | (19h 30m 03.99s , -15d 11m 03.0s) | C | 180 | 18.7 | Coadd 27477 | 2026-07-09 00:55:09 | MASTER-OAFA | (19h 30m 04.40s , -15d 09m 58.9s) | C | 60 | 18.5 | 27553 | 2026-07-09 00:56:25 | MASTER-OAFA | (19h 30m 08.71s , -15d 10m 56.6s) | C | 60 | 18.9 | 27631 | 2026-07-09 00:57:43 | MASTER-OAFA | (19h 30m 02.58s , -15d 11m 52.6s) | C | 60 | 19.0 | 27691 | 2026-07-09 00:57:43 | MASTER-OAFA | (19h 30m 02.58s , -15d 11m 52.6s) | C | 180 | 19.4 | Coadd 27710 | 2026-07-09 00:59:02 | MASTER-OAFA | (19h 30m 09.79s , -15d 11m 21.7s) | C | 60 | 19.0 | 27785 | 2026-07-09 01:00:17 | MASTER-OAFA | (19h 30m 06.55s , -15d 09m 52.2s) | C | 60 | 19.0 | 27894 | 2026-07-09 01:01:36 | MASTER-OAFA | (19h 30m 06.54s , -15d 11m 32.2s) | C | 120 | 18.9 | 28014 | 2026-07-09 01:01:36 | MASTER-OAFA | (19h 30m 06.54s , -15d 11m 32.2s) | C | 360 | 19.3 | Coadd 28033 | 2026-07-09 01:03:55 | MASTER-OAFA | (19h 30m 10.13s , -15d 10m 05.9s) | C | 120 | 18.9 | 28170 | 2026-07-09 01:06:12 | MASTER-OAFA | (19h 30m 03.95s , -15d 10m 29.8s) | C | 120 | 19.0 | 28416 | 2026-07-09 01:10:18 | MASTER-OAFA | (19h 30m 09.10s , -15d 10m 24.0s) | C | 120 | 18.8 | 28536 | 2026-07-09 01:10:18 | MASTER-OAFA | (19h 30m 09.10s , -15d 10m 24.0s) | C | 360 | 19.1 | Coadd 28551 | 2026-07-09 01:12:33 | MASTER-OAFA | (19h 30m 02.60s , -15d 11m 18.1s) | C | 120 | 18.6 | 28684 | 2026-07-09 01:14:46 | MASTER-OAFA | (19h 30m 09.44s , -15d 11m 01.1s) | C | 120 | 18.7 | 28823 | 2026-07-09 01:17:05 | MASTER-OAFA | (19h 30m 06.57s , -15d 09m 18.7s) | C | 120 | 18.7 | 28959 | 2026-07-09 01:19:21 | MASTER-OAFA | (19h 30m 06.54s , -15d 10m 33.6s) | C | 120 | 18.9 | 29098 | 2026-07-09 01:21:40 | MASTER-OAFA | (19h 30m 09.79s , -15d 08m 58.3s) | C | 120 | 19.1 | 29235 | 2026-07-09 01:23:57 | MASTER-OAFA | (19h 30m 03.25s , -15d 09m 51.7s) | C | 120 | 19.2 | 29373 | 2026-07-09 01:26:15 | MASTER-OAFA | (19h 30m 02.88s , -15d 08m 46.5s) | C | 120 | 19.3 | 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/45122. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43335] GRB 260709A: Fermi GBM Final Real-time Localization
by GCN Circulars 09 Jul '26

09 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45121 SUBJECT: GRB 260709A: Fermi GBM Final Real-time Localization DATE: 26/07/09 01:18:22 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 01:07:32 UT on 9 Jul 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260709A (trigger 805252057.543312 / 260709047). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 84.1, Dec = 74.0 (J2000 degrees, equivalent to J2000 05h 36m, 74d 00'), with a statistical uncertainty of 4.0 degrees. The angle from the Fermi LAT boresight is 106.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260709047/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260709047/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260709047/… View this GCN Circular online at https://gcn.nasa.gov/circulars/45121. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43334] IceCube-260708A - IceCube observation of a high-energy neutrino candidate track-like event
by GCN Circulars 08 Jul '26

08 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45120 SUBJECT: IceCube-260708A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 26/07/08 23:09:54 GMT FROM: A. Zegarelli at Ruhr University Bochum <azegarelli(a)icecube.wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 26-07-08 at 17:17:42.55 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_GOLD alert stream. Documentation regarding the alert streams and their astrophysical purity can be found here: https://gcn.nasa.gov/missions/icecube. This alert has an estimated false alarm rate of 0.1472 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/142827_7869742.amon) more sophisticated reconstruction algorithms have been applied offline. Some computational anomalies are observed in the primary offline reconstruction algorithm for this event, so the directional reconstruction results from the alternative offline algorithm are included in this event while these anomalies are investigated. With this alternative algorithm, the direction is refined to: Date: 26-07-08 Time: 17:17:42.55 UT RA: 292.81 (+0.48/-0.47 deg 90% PSF containment) J2000 Dec: -15.17 (+0.44/-0.48 deg 90% PSF containment) J2000 As announced in GCN Circular 43419 (https://gcn.nasa.gov/circulars/43419) IceCube alert notices for high-energy track alerts are now also streamed via Kafka. IceCube Gold/Bronze track alerts are available on the Kafka topic 'gcn.notices.icecube.gold_bronze_track_alerts'. The probability distribution of the true neutrino direction, allowing the extraction of precise 90% containment regions around the best-fit direction, is now available for revised reconstruction of high-energy track alerts. The corresponding sky map is distributed as a FITS file and follows the explicit naming convention IceCube-YYMMDDX, where YYMMDD indicates the date of the event and X is a letter distinguishing multiple alerts on the same day. The download link is provided through the GCN schema distributed via Kafka. Detailed documentation describing the alert distribution, schemas, and probability maps is available at: https://gcn.nasa.gov/missions/icecube. No known gamma-ray sources listed in the Fermi LAT 16-year Source List (FL16Y) are located within the 90% uncertainty region of this event. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu View this GCN Circular online at https://gcn.nasa.gov/circulars/45120. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43333] LAT GRB260708.42: Global MASTER-Net observations report
by GCN Circulars 08 Jul '26

08 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45119 SUBJECT: LAT GRB260708.42: Global MASTER-Net observations report DATE: 26/07/08 22:55:59 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) was pointed to the LAT GRB260708.42 (trigger No 805198281,15h 02m 26.40s , -44d 04m 12.0s, R=0.369833) errorbox 23412 sec after notice time and 44923 sec after trigger time at 2026-07-08 22:40:00 UT, with upper limit up to 18.6 mag. Observations started at twilight. The observations began at zenith distance = 25 deg. The sun altitude is -11.4 deg. The galactic latitude b = 12 deg., longitude l = 327 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3420593 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 44954 | 2026-07-08 22:40:00 | MASTER-OAFA | (15h 01m 59.54s , -43d 52m 20.2s) | C | 60 | 17.8 | 45029 | 2026-07-08 22:41:16 | MASTER-OAFA | (15h 02m 05.06s , -43d 53m 19.4s) | C | 60 | 18.1 | 45108 | 2026-07-08 22:42:34 | MASTER-OAFA | (15h 02m 00.49s , -43d 54m 17.7s) | C | 60 | 18.6 | 45182 | 2026-07-08 22:43:49 | MASTER-OAFA | (15h 02m 05.32s , -43d 54m 07.3s) | C | 60 | 18.5 | 45255 | 2026-07-08 22:45:02 | MASTER-OAFA | (15h 02m 02.92s , -43d 52m 33.7s) | C | 60 | 17.7 | 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/45119. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 43332] GRB260708B: MAXI/GSC detection
by GCN Circulars 08 Jul '26

08 Jul '26

TITLE: GCN CIRCULAR NUMBER: 45118 SUBJECT: GRB260708B: MAXI/GSC detection DATE: 26/07/08 18:52:03 GMT FROM: nakajima.motoki(a)nihon-u.ac.jp M. Nakajima, H. Negoro, K. Saito, T. Yokoyama, M. Wada (Nihon U.), T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, S. Sugita, Y. Kawakubo, H. Hiramatsu, A. Yoshida (AGU), Y. Tsuboi, Y. Ishihara, H. Ogaki (Chuo U.), M. Shidatsu, C. Kang, M. Uenishi, T. Usuki, S. Yatsuzuka, H. Aoe (Ehime U.), I. Takahashi, Y. Yatsu (Science Tokyo), S. Nakahira, S. Ueno, H. Tomida, M. Kurihara (JAXA), Y. Ueda, K. Fujiwara, S. Kobayashi (Kyoto U.), M. Yamauchi, M. Nishio, C. Hiraizumi (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Sugizaki (Kanazawa U.), W. Iwakiri (Chiba U.), T. Kawamuro (Osaka U.), S. Yamada (Tohoku U), S. Ogawa (TUS) report on behalf of the MAXI team: The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 16:43:12 UT on July 8 2026. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (342.139 deg, -3.776 deg) = (22 48 33, -03 46 33) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.22 deg and 0.18 deg, respectively. The roll angle of long axis from the north direction is 167.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 172 +- 25 mCrab (4.0-10.0keV, 1 sigma error). Without assumptions on the source constancy, we obtain a rectangular error box for the transient source with the following corners: (341.215, -2.825) deg = (22 44 51, -02 49 30) (J2000) (340.981, -3.128) deg = (22 43 55, -03 07 40) (J2000) (342.971, -4.662) deg = (22 51 53, -04 39 43) (J2000) (343.205, -4.358) deg = (22 52 49, -04 21 28) (J2000) There was no significant excess flux in the previous transit at 15:10 UT and in the next transit at 18:16 UT with an upper limit of 20 mCrab for each. View this GCN Circular online at https://gcn.nasa.gov/circulars/45118. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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